{"id":2772,"date":"2024-04-02T10:54:00","date_gmt":"2024-04-02T10:54:00","guid":{"rendered":"https:\/\/cheapsslweb.com\/resources\/?p=2772"},"modified":"2025-12-24T04:24:18","modified_gmt":"2025-12-24T04:24:18","slug":"how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error","status":"publish","type":"post","link":"https:\/\/cheapsslweb.com\/resources\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error","title":{"rendered":"How to Fix Cloudflare  Error 520: Web Server Is Returning an Unknown Error?"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">A visitor enthusiastically hops onto your site, searching for some information. When they click on it, all they see is this message: \u201cError 520: Web Server Is Returning an Unknown Error.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">They try again, and the same thing appears. Feeling disappointed, they left your site and visited your competitor&#8217;s site.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">There, you lost a potential lead!<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Not only this, but you may also realize you aren&#8217;t able to log in to the site dashboard. Thus, resolving Error 520 is important for continuous access and provides the best user experience.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In this article, we&#8217;ll understand what Error 520 is, its possible causes, and how to fix Error 520.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Let&#8217;s dive right in!<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">Protect your Website&#8217;s Sensitive Data with Trusted SSL\/TLS Certificates! <\/p>\n<cite>~ <a href=\"https:\/\/cheapsslweb.com\/\">Starts at just $3.99\/yr<\/a><\/cite><\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">What\u2019s Cloudflare Error 520?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u201cError 520: web server is returning an unknown error\u201d implies that Cloudflare cannot connect to your original web server. Instead, the server returns an unknown, unexpected, or empty response to Cloudflare.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Thus, if you encounter the above message when using Cloudflare, know that the connection is not established. This also means the server can\u2019t process the user request, hinting at the website\u2019s unavailability.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Causes of Error 520<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">You may receive Error 520 due to several reasons:<\/p>\n\n\n\n<ul start=\"1\" class=\"wp-block-list\">\n<li><strong>TCP timeouts: <\/strong>It occurs when the server\u2019s default idle timeout (300 s) exceeds the TCP idle timeout. Consequently, no connection is established between the server and the client.<\/li>\n\n\n\n<li><strong>TLS\/SSL handshake issues<\/strong>: If there\u2019s any issue in the TLS\/SSL certificate on the origin web server, it results in <a href=\"https:\/\/cheapsslweb.com\/blog\/how-to-fix-ssl-tls-handshake-failed-error\">handshake failure<\/a>. The issue could be the certificate\u2019s expiry, invalidity, or misconfiguration.<\/li>\n\n\n\n<li><strong>Server Crashes<\/strong>: A website\u2019s PHP-based coding might freeze or crash, preventing the server from processing user requests.<\/li>\n\n\n\n<li><strong>Denied IP addresses<\/strong>: Your firewall might block some IP addresses not in its allowlist, rejecting the connection.<\/li>\n\n\n\n<li><strong>Header and Cookie Issues<\/strong>: Too many cookies or large headers (exceeding 16 kb) during the connection may result in server overloads, resulting in Error 520. Also, if the request has insufficient header information, the server can\u2019t correctly process the request.<\/li>\n\n\n\n<li><strong>Incorrect DNS Records or .htaccess file<\/strong>: If the DNS records corresponding to the server are incorrect, the browser can\u2019t find the server, and you get Error 520. Similarly, if the site\u2019s code has a flawed .htaccess file, the server can&#8217;t properly process the user request, resulting in Error 520.<\/li>\n\n\n\n<li><strong>Empty Server Response<\/strong>: If the browser doesn\u2019t receive any server response, it can\u2019t show anything.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Also Read:<\/strong> <a href=\"https:\/\/cheapsslweb.com\/resources\/how-to-fix-cloudflare-http-error-526-invalid-ssl-certificate\">How to Fix Cloudflare HTTP Error 526 : Invalid SSL Certificate?<\/a><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">How to Fix Cloudflare Error 520?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Follow the steps below to fix \u201cError 520: web server is returning an unknown error\u201d:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Try Connecting Again<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Sometimes, the error could be temporary. Issues like high traffic volumes or server overloading can cause the server or network to deny or delay requests. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When this happens, it will start fixing the issue or scale up resources automatically to accommodate the load. Thus, it will require some time to process the requests.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So, wait for a while and refresh the web page to check if the problem is resolved. <strong>If not, there are other methods you can try.<\/strong><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Pause Cloudflare<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">If you are using Cloudflare\u2019s reverse proxy and getting Error 520, try disabling Cloudflare. <strong>Follow the below steps to do it:<\/strong><\/p>\n\n\n\n<ul start=\"1\" class=\"wp-block-list\">\n<li>Log-in to <strong>Cloudflare<\/strong>.<\/li>\n\n\n\n<li>On your screen&#8217;s left-hand panel, find \u201c<strong>Overview<\/strong>\u201d and click on it.<\/li>\n\n\n\n<li>Scroll down to reach \u201c<strong>Advanced Actions<\/strong>\u201d.<\/li>\n\n\n\n<li>You will find the option \u201c<strong>Pause Cloudflare on Site<\/strong>\u201d to disable Cloudflare temporarily from your site.<\/li>\n\n\n\n<li>Hit \u201c<strong>Confirm<\/strong>\u201d.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Check Error Logs<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Error logs provide crucial information, which will help you resolve the issue faster. <strong>It includes data, such as:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Incident and it&#8217;s root cause<\/li>\n\n\n\n<li>Source<\/li>\n\n\n\n<li>Date and time<\/li>\n\n\n\n<li>Client IP address<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">However, creating error logs can differ based on the hosting service. <strong>For cPanel users, here&#8217;s how you can check error logs:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Log in to your <strong>cPanel<\/strong>.<\/li>\n\n\n\n<li>Inside your dashboard, locate \u201c<strong>Metrics<\/strong>\u201d.<\/li>\n\n\n\n<li>Locate \u201c<strong>Errors<\/strong>\u201d and click on it. It will show you up to 300 recent error logs.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Inspect Cookies and Headers<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">If the overall request header exceeds 32 kb, it will show Error 520. Also, too many cookies increase the header size. Thus, optimizing cookies and headers is essential, keeping it under 16 kb per header and 32 kb overall so user requests can be processed without hassles. <strong>Steps to do it are as follows:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Open the page showing Error 520.<\/li>\n\n\n\n<li>Right-click on the web page and choose \u201c<strong>Inspect<\/strong>\u201d. It will <strong>open developer tools<\/strong>.<\/li>\n\n\n\n<li>Inside the panel, look for \u201c<strong>Network<\/strong>\u201d and click on it.<\/li>\n\n\n\n<li>Check the box for \u201c<strong>Preserve log<\/strong>\u201d.<\/li>\n\n\n\n<li>Clear network activities by clicking on \u201c<strong>Clear<\/strong>\u201d.<\/li>\n\n\n\n<li>Capture new network activities by reloading the page.<\/li>\n\n\n\n<li>Right-click on the page anywhere and choose \u201c<strong>Save all as HAR with content<\/strong>\u201d.<\/li>\n\n\n\n<li>Select a location to s<strong>ave this HAR file on the computer<\/strong>. Click on \u201c<strong>Save<\/strong>\u201d.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Correct DNS Records<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Incorrect DNS records can cause Error 520, so check and correct the records. <strong>Here&#8217;s how to do it:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Login to your <strong>DNS account<\/strong>. You can also do it through the hosting provider.<\/li>\n\n\n\n<li>Find out whether the records are correct or not, like <strong>CNAME<\/strong>.<\/li>\n\n\n\n<li>Update the <strong>records.<\/strong><\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Disable .htaccess<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">.htaccess or hypertext access files are configuration files for Apache-based websites. Sometimes, if this file gets corrupted or has other flaws, the web server can&#8217;t process user requests.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So, if your site is hosted on an Apache Web server, disable the .htaccess file to resolve the issue. Also, ensure your firewall or .htaccess file doesn&#8217;t have settings to block Cloudflare IP addresses. <strong>To disable the file, follow the steps:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Open .htaccess file<\/strong>.<\/li>\n\n\n\n<li>Change \u201c<strong>AllowOverride<\/strong>\u201d to None.<\/li>\n\n\n\n<li><strong>Save the file changes. Restart Apache<\/strong>.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Use cURL<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">cURL or client URL is a command that you can use to send HTTPS\/ HTTP requests and fix HTTP errors. <strong>So, run the cURL in the command terminal by following these steps:<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>For Windows:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Pressing <strong>Windows + R keys <\/strong>from your keyboard<\/li>\n\n\n\n<li>Typing \u201c<strong>cmd<\/strong>\u201d<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>For macOS:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Go to \u201c<strong>Applications<\/strong>\u201c.<\/li>\n\n\n\n<li>Click on \u201c<strong>Utilities<\/strong>\u201d.<\/li>\n\n\n\n<li>Choose \u201c<strong>Terminal<\/strong>\u201d.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Thus will trigger a request to the web server and obtain a complete response.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">cURL format: <em><strong>curl -I http:\/\/xyz.com<\/strong><\/em><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Running this command will help you understand an error and a successful response. Thus, you can check whether the server is configured correctly.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Restart PHP<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Sometimes, Error 520 can occur due to PHP code crashing or malfunctioning. So, consider restarting PHP. It might differ with the type of server and software the server runs. <strong>To restart PHP:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Log-in to your <strong>server hosting account <\/strong>or web server<\/li>\n\n\n\n<li>Find the site&#8217;s configuration file. It can be <strong>php.d, php.ini, conf.d<\/strong>, etc.<\/li>\n\n\n\n<li><strong>Review the file to check for flaws<\/strong> in terms of size, execution time, etc. Edit if something isn&#8217;t right.<\/li>\n\n\n\n<li><strong>Restart PHP<\/strong> by entering the <strong>server command<\/strong>.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Seek Support<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">If you have tried everything and still Error 520 keeps showing, contact Cloudflare&#8217;s support team.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Also Read:<\/strong> <a href=\"https:\/\/cheapsslweb.com\/resources\/what-is-http-500-internal-server-error-and-how-to-fix-it\">What is \u201cHTTP 500 Internal Server Error\u201d? How to Fix It?<\/a><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Conclusion<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Error 520 is a serious issue that you must resolve quickly to have seamless access to your site dashboard and deliver the best user experience. So, if you face Error 520, resolve it quickly in various ways.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A visitor enthusiastically hops onto your site, searching for some information. When they click on it, all they see is this message: \u201cError 520: Web Server Is Returning an Unknown Error. They try again, and the same thing appears. Feeling disappointed, they left your site and visited your competitor&#8217;s site. There, you lost a potential<span class=\"morelink d-block mt-3\"><a href=\"https:\/\/cheapsslweb.com\/resources\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error\">Read More<\/a><\/span><\/p>\n","protected":false},"author":1,"featured_media":2802,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[25],"tags":[505,216,217,218],"class_list":["post-2772","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-ssl-errors-guide","tag-error-520-fix","tag-fix-cloudflare-error-520","tag-troubleshooting-cloudflare-5xx-errors","tag-web-server-is-returning-an-unknown-error-cloudflare","entry"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.7 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Fix Cloudflare Error 520: Web Server Is Returning an Unknown Error<\/title>\n<meta name=\"description\" content=\"Error 520 occurs when the origin server returns an empty, unknown, or unexpected response to Cloudflare. Follow the steps to fix Cloudflare error 520.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/cheapsslweb.com\/resources\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Fix Cloudflare Error 520: Web Server Is Returning an Unknown Error\" \/>\n<meta property=\"og:description\" content=\"Error 520 occurs when the origin server returns an empty, unknown, or unexpected response to Cloudflare. Follow the steps to fix Cloudflare error 520.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/cheapsslweb.com\/resources\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error\" \/>\n<meta property=\"og:site_name\" content=\"CheapSSLWeb.com Resources\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/cheapsslweb\" \/>\n<meta property=\"article:published_time\" content=\"2024-04-02T10:54:00+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2025-12-24T04:24:18+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/cheapsslweb.com\/resources\/wp-content\/uploads\/2024\/03\/cloudflair-error-520-jpg.webp\" \/>\n\t<meta property=\"og:image:width\" content=\"960\" \/>\n\t<meta property=\"og:image:height\" content=\"621\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"Janki Mehta\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@cheapsslweb\" \/>\n<meta name=\"twitter:site\" content=\"@cheapsslweb\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error\"},\"author\":{\"name\":\"Janki Mehta\",\"@id\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/#\\\/schema\\\/person\\\/c7d26eacacd9392c23be9d82e9af145e\"},\"headline\":\"How to Fix Cloudflare Error 520: Web Server Is Returning an Unknown Error?\",\"datePublished\":\"2024-04-02T10:54:00+00:00\",\"dateModified\":\"2025-12-24T04:24:18+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error\"},\"wordCount\":1190,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/wp-content\\\/uploads\\\/2024\\\/03\\\/fix-cloudflare-error-520-jpg.webp\",\"keywords\":[\"Error 520 Fix\",\"Fix Cloudflare Error 520\",\"Troubleshooting Cloudflare 5XX errors\",\"Web Server is Returning an Unknown Error Cloudflare\"],\"articleSection\":[\"SSL Errors &amp; Guide\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error\",\"url\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error\",\"name\":\"Fix Cloudflare Error 520: Web Server Is Returning an Unknown Error\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/wp-content\\\/uploads\\\/2024\\\/03\\\/fix-cloudflare-error-520-jpg.webp\",\"datePublished\":\"2024-04-02T10:54:00+00:00\",\"dateModified\":\"2025-12-24T04:24:18+00:00\",\"description\":\"Error 520 occurs when the origin server returns an empty, unknown, or unexpected response to Cloudflare. Follow the steps to fix Cloudflare error 520.\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error#primaryimage\",\"url\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/wp-content\\\/uploads\\\/2024\\\/03\\\/fix-cloudflare-error-520-jpg.webp\",\"contentUrl\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/wp-content\\\/uploads\\\/2024\\\/03\\\/fix-cloudflare-error-520-jpg.webp\",\"width\":960,\"height\":621,\"caption\":\"Resolve Cloudflare Error 520\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"How to Fix Cloudflare Error 520: Web Server Is Returning an Unknown Error?\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/#website\",\"url\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/\",\"name\":\"CheapSSLWeb.com\",\"description\":\"SSL Errors and Installation Tutorials\",\"publisher\":{\"@id\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/#organization\"},\"alternateName\":\"Cheap SSL Web\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/#organization\",\"name\":\"CheapSSLWeb\",\"alternateName\":\"Cheap SSL Web\",\"url\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/wp-content\\\/uploads\\\/2022\\\/03\\\/logo.png\",\"contentUrl\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/wp-content\\\/uploads\\\/2022\\\/03\\\/logo.png\",\"width\":177,\"height\":60,\"caption\":\"CheapSSLWeb\"},\"image\":{\"@id\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/#\\\/schema\\\/logo\\\/image\\\/\"},\"sameAs\":[\"https:\\\/\\\/www.facebook.com\\\/cheapsslweb\",\"https:\\\/\\\/x.com\\\/cheapsslweb\",\"https:\\\/\\\/www.linkedin.com\\\/company\\\/cheapsslweb\\\/\",\"https:\\\/\\\/www.pinterest.com\\\/cheapsslweb\\\/\",\"https:\\\/\\\/www.instagram.com\\\/cheapsslweb\\\/\"]},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/#\\\/schema\\\/person\\\/c7d26eacacd9392c23be9d82e9af145e\",\"name\":\"Janki Mehta\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/1fba817ef81065f1393461fc3a0d85c40f2cc826919819ea4df4b12d76566e62?s=96&d=https%3A%2F%2Fcheapsslweb.com%2Fblog%2Fwp-content%2Fuploads%2F2023%2F02%2Fjanki-mehta-jpg.webp&r=g\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/1fba817ef81065f1393461fc3a0d85c40f2cc826919819ea4df4b12d76566e62?s=96&d=https%3A%2F%2Fcheapsslweb.com%2Fblog%2Fwp-content%2Fuploads%2F2023%2F02%2Fjanki-mehta-jpg.webp&r=g\",\"contentUrl\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/1fba817ef81065f1393461fc3a0d85c40f2cc826919819ea4df4b12d76566e62?s=96&d=https%3A%2F%2Fcheapsslweb.com%2Fblog%2Fwp-content%2Fuploads%2F2023%2F02%2Fjanki-mehta-jpg.webp&r=g\",\"caption\":\"Janki Mehta\"},\"description\":\"Janki Mehta is a Cyber-Security Enthusiast having 7+ years of experience and knowledge about Encryption, Digital Certificates and Online Security, She helps online users to stay safe and protect their online presence. Explore SSL Errors, Installation Guide and Security Tutorials for Safe Browsing and Web Security Experience.\",\"sameAs\":[\"https:\\\/\\\/cheapsslweb.com\\\/\",\"https:\\\/\\\/www.linkedin.com\\\/in\\\/pw-jankimehta\\\/\"],\"url\":\"https:\\\/\\\/cheapsslweb.com\\\/resources\\\/author\\\/janki-mehta\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Fix Cloudflare Error 520: Web Server Is Returning an Unknown Error","description":"Error 520 occurs when the origin server returns an empty, unknown, or unexpected response to Cloudflare. Follow the steps to fix Cloudflare error 520.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/cheapsslweb.com\/resources\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error","og_locale":"en_US","og_type":"article","og_title":"Fix Cloudflare Error 520: Web Server Is Returning an Unknown Error","og_description":"Error 520 occurs when the origin server returns an empty, unknown, or unexpected response to Cloudflare. Follow the steps to fix Cloudflare error 520.","og_url":"https:\/\/cheapsslweb.com\/resources\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error","og_site_name":"CheapSSLWeb.com Resources","article_publisher":"https:\/\/www.facebook.com\/cheapsslweb","article_published_time":"2024-04-02T10:54:00+00:00","article_modified_time":"2025-12-24T04:24:18+00:00","og_image":[{"width":960,"height":621,"url":"https:\/\/cheapsslweb.com\/resources\/wp-content\/uploads\/2024\/03\/cloudflair-error-520-jpg.webp","type":"image\/jpeg"}],"author":"Janki Mehta","twitter_card":"summary_large_image","twitter_creator":"@cheapsslweb","twitter_site":"@cheapsslweb","schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/cheapsslweb.com\/resources\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error#article","isPartOf":{"@id":"https:\/\/cheapsslweb.com\/resources\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error"},"author":{"name":"Janki Mehta","@id":"https:\/\/cheapsslweb.com\/resources\/#\/schema\/person\/c7d26eacacd9392c23be9d82e9af145e"},"headline":"How to Fix Cloudflare Error 520: Web Server Is Returning an Unknown Error?","datePublished":"2024-04-02T10:54:00+00:00","dateModified":"2025-12-24T04:24:18+00:00","mainEntityOfPage":{"@id":"https:\/\/cheapsslweb.com\/resources\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error"},"wordCount":1190,"commentCount":0,"publisher":{"@id":"https:\/\/cheapsslweb.com\/resources\/#organization"},"image":{"@id":"https:\/\/cheapsslweb.com\/resources\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error#primaryimage"},"thumbnailUrl":"https:\/\/cheapsslweb.com\/resources\/wp-content\/uploads\/2024\/03\/fix-cloudflare-error-520-jpg.webp","keywords":["Error 520 Fix","Fix Cloudflare Error 520","Troubleshooting Cloudflare 5XX errors","Web Server is Returning an Unknown Error Cloudflare"],"articleSection":["SSL Errors &amp; Guide"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/cheapsslweb.com\/resources\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error#respond"]}]},{"@type":"WebPage","@id":"https:\/\/cheapsslweb.com\/resources\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error","url":"https:\/\/cheapsslweb.com\/resources\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error","name":"Fix Cloudflare Error 520: Web Server Is Returning an Unknown Error","isPartOf":{"@id":"https:\/\/cheapsslweb.com\/resources\/#website"},"primaryImageOfPage":{"@id":"https:\/\/cheapsslweb.com\/resources\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error#primaryimage"},"image":{"@id":"https:\/\/cheapsslweb.com\/resources\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error#primaryimage"},"thumbnailUrl":"https:\/\/cheapsslweb.com\/resources\/wp-content\/uploads\/2024\/03\/fix-cloudflare-error-520-jpg.webp","datePublished":"2024-04-02T10:54:00+00:00","dateModified":"2025-12-24T04:24:18+00:00","description":"Error 520 occurs when the origin server returns an empty, unknown, or unexpected response to Cloudflare. Follow the steps to fix Cloudflare error 520.","breadcrumb":{"@id":"https:\/\/cheapsslweb.com\/resources\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/cheapsslweb.com\/resources\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/cheapsslweb.com\/resources\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error#primaryimage","url":"https:\/\/cheapsslweb.com\/resources\/wp-content\/uploads\/2024\/03\/fix-cloudflare-error-520-jpg.webp","contentUrl":"https:\/\/cheapsslweb.com\/resources\/wp-content\/uploads\/2024\/03\/fix-cloudflare-error-520-jpg.webp","width":960,"height":621,"caption":"Resolve Cloudflare Error 520"},{"@type":"BreadcrumbList","@id":"https:\/\/cheapsslweb.com\/resources\/how-to-fix-cloudflares-error-520-web-server-is-returning-an-unknown-error#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/cheapsslweb.com\/resources\/"},{"@type":"ListItem","position":2,"name":"How to Fix Cloudflare Error 520: Web Server Is Returning an Unknown Error?"}]},{"@type":"WebSite","@id":"https:\/\/cheapsslweb.com\/resources\/#website","url":"https:\/\/cheapsslweb.com\/resources\/","name":"CheapSSLWeb.com","description":"SSL Errors and Installation Tutorials","publisher":{"@id":"https:\/\/cheapsslweb.com\/resources\/#organization"},"alternateName":"Cheap SSL Web","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/cheapsslweb.com\/resources\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/cheapsslweb.com\/resources\/#organization","name":"CheapSSLWeb","alternateName":"Cheap SSL Web","url":"https:\/\/cheapsslweb.com\/resources\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/cheapsslweb.com\/resources\/#\/schema\/logo\/image\/","url":"https:\/\/cheapsslweb.com\/resources\/wp-content\/uploads\/2022\/03\/logo.png","contentUrl":"https:\/\/cheapsslweb.com\/resources\/wp-content\/uploads\/2022\/03\/logo.png","width":177,"height":60,"caption":"CheapSSLWeb"},"image":{"@id":"https:\/\/cheapsslweb.com\/resources\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/cheapsslweb","https:\/\/x.com\/cheapsslweb","https:\/\/www.linkedin.com\/company\/cheapsslweb\/","https:\/\/www.pinterest.com\/cheapsslweb\/","https:\/\/www.instagram.com\/cheapsslweb\/"]},{"@type":"Person","@id":"https:\/\/cheapsslweb.com\/resources\/#\/schema\/person\/c7d26eacacd9392c23be9d82e9af145e","name":"Janki Mehta","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/secure.gravatar.com\/avatar\/1fba817ef81065f1393461fc3a0d85c40f2cc826919819ea4df4b12d76566e62?s=96&d=https%3A%2F%2Fcheapsslweb.com%2Fblog%2Fwp-content%2Fuploads%2F2023%2F02%2Fjanki-mehta-jpg.webp&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/1fba817ef81065f1393461fc3a0d85c40f2cc826919819ea4df4b12d76566e62?s=96&d=https%3A%2F%2Fcheapsslweb.com%2Fblog%2Fwp-content%2Fuploads%2F2023%2F02%2Fjanki-mehta-jpg.webp&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/1fba817ef81065f1393461fc3a0d85c40f2cc826919819ea4df4b12d76566e62?s=96&d=https%3A%2F%2Fcheapsslweb.com%2Fblog%2Fwp-content%2Fuploads%2F2023%2F02%2Fjanki-mehta-jpg.webp&r=g","caption":"Janki Mehta"},"description":"Janki Mehta is a Cyber-Security Enthusiast having 7+ years of experience and knowledge about Encryption, Digital Certificates and Online Security, She helps online users to stay safe and protect their online presence. Explore SSL Errors, Installation Guide and Security Tutorials for Safe Browsing and Web Security Experience.","sameAs":["https:\/\/cheapsslweb.com\/","https:\/\/www.linkedin.com\/in\/pw-jankimehta\/"],"url":"https:\/\/cheapsslweb.com\/resources\/author\/janki-mehta"}]}},"_links":{"self":[{"href":"https:\/\/cheapsslweb.com\/resources\/wp-json\/wp\/v2\/posts\/2772","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cheapsslweb.com\/resources\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cheapsslweb.com\/resources\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cheapsslweb.com\/resources\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/cheapsslweb.com\/resources\/wp-json\/wp\/v2\/comments?post=2772"}],"version-history":[{"count":7,"href":"https:\/\/cheapsslweb.com\/resources\/wp-json\/wp\/v2\/posts\/2772\/revisions"}],"predecessor-version":[{"id":5270,"href":"https:\/\/cheapsslweb.com\/resources\/wp-json\/wp\/v2\/posts\/2772\/revisions\/5270"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cheapsslweb.com\/resources\/wp-json\/wp\/v2\/media\/2802"}],"wp:attachment":[{"href":"https:\/\/cheapsslweb.com\/resources\/wp-json\/wp\/v2\/media?parent=2772"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cheapsslweb.com\/resources\/wp-json\/wp\/v2\/categories?post=2772"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cheapsslweb.com\/resources\/wp-json\/wp\/v2\/tags?post=2772"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}