{"id":27772,"date":"2024-03-07T22:38:35","date_gmt":"2024-03-07T22:38:35","guid":{"rendered":"https:\/\/10web.io\/blog\/?p=27772"},"modified":"2024-03-07T22:40:32","modified_gmt":"2024-03-07T22:40:32","slug":"cannot-modify-header-information","status":"publish","type":"post","link":"https:\/\/10web.io\/blog\/cannot-modify-header-information\/","title":{"rendered":"Troubleshooting the &#8220;Cannot Modify Header Information&#8221; Error"},"content":{"rendered":"<p><span style=\"font-weight: 400;\">The &#8220;Cannot Modify Header Information \u2013 Headers Already Sent By&#8221; error is one of those classic roadblocks that developers, especially those working with WordPress, encounter from time to time. This error is one such glitch in the matrix that catches many off guard. This error message pops up when your website&#8217;s PHP code has already sent output (like whitespace or HTML) before it attempts to send HTTP headers. Since headers need to go first, this situation is a big no-no in PHP land. <\/span><\/p>\n<p><span style=\"font-weight: 400;\">Let&#8217;s unravel this issue together, understanding its roots and exploring methods to smooth it out, ensuring your digital space remains as welcoming and error-free as possible.<\/span><\/p>\n<h2 id=\"understanding-the-culprit-behind-the-curtain\"><span style=\"font-weight: 400;\">Understanding the culprit behind the curtain<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">This error message pops up when <a href=\"https:\/\/10web.io\/glossary\/php\/\">PHP<\/a> attempts to send HTTP headers after the output has begun. Simply put, PHP files must send headers (instructions) to the browser before any other output. If something interrupts this sequence\u2014be it a rogue whitespace, an unexpected echo statement, or even an unnoticed output from a plugin\u2014the server raises a flag, and you&#8217;re greeted with this error. <\/span><\/p>\n<p><span style=\"font-weight: 400;\">The error message is rather courteous, though, explicitly pointing out the file and the precise line of code causing the hiccup. This breadcrumb trail is invaluable for troubleshooting, leading you directly to the source of the disruption.<\/span><\/p>\n<h2 id=\"variations-on-a-theme\"><span style=\"font-weight: 400;\">Variations on a theme<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">The error manifests in various contexts, influenced by factors such as the specific PHP file in question, the hosting environment, or even the WordPress theme or plugin you&#8217;re using. Despite the variations, the essence of the error remains consistent\u2014PHP headers being sent post-output.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Here are some common variations you might encounter:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Warning: Cannot modify header information &#8211; headers already sent by (output started at \/path\/to\/the\/file.php:line number)<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Error in a plugin or theme file specifically pointing to where the output started<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Direct references to whitespace or output before the header() call in PHP<\/span><\/li>\n<\/ul>\n<h2 id=\"dissecting-the-causes\"><span style=\"font-weight: 400;\">Dissecting the causes<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">At its core, this error can spring from a few typical sources:<\/span><\/p>\n<p><b>Whitespaces or new lines<\/b><span style=\"font-weight: 400;\">: A common culprit is extra spaces before the `&lt;?php` tag or after the `?&gt;` closing tag in your PHP files. PHP, being whitespace-sensitive in this context, interprets these as output, leading to the error.<\/span><\/p>\n<p><b>HTML before PHP headers<\/b><span style=\"font-weight: 400;\">: Placing HTML code before PHP header functions is like putting the cart before the horse; it just doesn&#8217;t work.<\/span><\/p>\n<p><b>Echo or print statements before headers:<\/b><span style=\"font-weight: 400;\">\u00a0Echoing or printing any content before calling header-related functions triggers this error, as it constitutes output.<\/span><\/p>\n<p><b>Plugin misbehavior<\/b><span style=\"font-weight: 400;\">: Sometimes, the error can be traced back to a plugin, especially if it outputs content unexpectedly before header functions run.<\/span><\/p>\n<p><b>Plugin or theme code issues<\/b><span style=\"font-weight: 400;\">: Similar to plugins, themes can also inadvertently introduce output before headers, especially in functions.php or other theme-related PHP files.<\/span><\/p>\n<h3 id=\"following-the-clues\"><span style=\"font-weight: 400;\">Following the clues<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">An example of a warning message from the &#8220;Cannot modify header information &#8211; headers already sent by&#8221; error typically points you right to the source of the issue. It usually looks something like this:<\/span><\/p>\n<pre><span style=\"font-weight: 400;\">Warning: Cannot modify header information - headers already sent by (output started at \/path\/to\/php\/file.php:2) in \/path\/to\/another\/php\/file.php on line 25<\/span><\/pre>\n<p><span style=\"font-weight: 400;\">Let&#8217;s break this down a bit. This message is PHP&#8217;s way of telling you, &#8220;Hey, I was about to send some headers to the browser, but I couldn&#8217;t because the output has already started somewhere else.&#8221; It points out a couple of key things:<\/span><\/p>\n<ol>\n<li><span style=\"font-weight: 400;\"><strong>The file and the line where the output started<\/strong>: `\/path\/to\/php\/file.php:2` indicates that the output (like HTML, blank spaces, or even an error message) started on line 2 of the specified file.<\/span><\/li>\n<li><span style=\"font-weight: 400;\"><strong>The file and line where it tried to modify the headers<\/strong>: `\/path\/to\/another\/php\/file.php on line 25` shows where PHP attempted to send a header or modify an existing one but was stopped in its tracks because output had already begun.<\/span><\/li>\n<\/ol>\n<p><span style=\"font-weight: 400;\">This error usually means there&#8217;s something being sent to the browser before it was supposed to. It could be as simple as a space or newline before the opening `&lt;?php` tag, or after the closing `?&gt;` tag, or it might be something more complex like an echo statement placed before a session start or a header redirection.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Solving it requires some detective work, including tracing the output back to its beginning and ensuring that headers are modified before any output is sent to the browser. <\/span><\/p>\n<h2 id=\"fixing-the-issue\"><span style=\"font-weight: 400;\">Fixing the issue<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">Now, let&#8217;s navigate the path to resolution, focusing on practical steps to rectify this issue.<\/span><\/p>\n<h3 id=\"1-fix-the-error-with-the-plugin-or-theme-editor\"><span style=\"font-weight: 400;\">1. Fix the error with the plugin or theme editor<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">Upon identifying the problematic file and line (courtesy of the error message), the first step is editing the file. For WordPress users, the theme or plugin editor offers a straightforward way to remove unwanted whitespaces or correct the output order. However, tread lightly; direct modifications can have ripple effects.<\/span><\/p>\n<h4><span style=\"font-weight: 400;\">Dive into the theme or plugin editor<\/span><\/h4>\n<p><span style=\"font-weight: 400;\">Start by locating the file identified by the error message (say, the `functions.php` file in your theme). Accessing the Theme Editor via `Appearance &gt; Theme Editor` in your WordPress dashboard can help you find and squash this bug. Once there, navigate to the problematic file.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/cannot-modify-header-information.jpg\" alt=\"Troubleshooting the cannot modify header information error in the WordPress theme editor.\" width=\"1560\" height=\"875\" class=\"alignnone size-full wp-image-27774\" srcset=\"https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/cannot-modify-header-information.jpg 1560w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/cannot-modify-header-information-742x416.jpg 742w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/cannot-modify-header-information-1484x832.jpg 1484w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/cannot-modify-header-information-150x84.jpg 150w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/cannot-modify-header-information-768x431.jpg 768w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/cannot-modify-header-information-1536x862.jpg 1536w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/cannot-modify-header-information-371x208.jpg 371w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/cannot-modify-header-information-600x337.jpg 600w\" sizes=\"auto, (max-width: 1560px) 100vw, 1560px\" \/><\/p>\n<p><span style=\"font-weight: 400;\">The issue often lies with whitespaces before the opening `&lt;?php` tag or after the closing `?&gt;` tag. Scan for any unexpected whitespaces and remove them. Once you&#8217;re finished editing, hit &#8220;Update File&#8221; and try accessing your site again.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">For plugin-related issues, a similar approach applies. Head over to `Plugins &gt; Plugin Editor`, select the troublesome plugin referenced by the error, and inspect the indicated file for sneaky spaces or extra lines.<\/span><\/p>\n<h3 id=\"when-in-doubt-reinstall-the-plugin\"><span style=\"font-weight: 400;\">When in doubt, reinstall the plugin<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">Sometimes, the error can be a bit more stubborn. If it&#8217;s tied to a specific plugin and editing doesn&#8217;t cut it, consider removing and reinstalling the plugin. This can act as a reset button, potentially clearing the error. However, be warned: you might lose your plugin settings, so weigh your options.<\/span><\/p>\n<h3 id=\"2-edit-the-problem-file-via-ftp-sftp\"><span style=\"font-weight: 400;\">2. Edit the problem file via FTP\/SFTP<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">For errors beyond the reach of WordPress&#8217;s built-in editors or for non-WordPress PHP files, FTP or SFTP access becomes your toolkit. This approach allows you to edit the offending file on your server directly, be it `wp-config.php`, a theme&#8217;s `functions.php`, or any other file flagged by the error message. Remember, it&#8217;s about finding and fixing the source of premature output\u2014whether it&#8217;s removing whitespaces, adjusting the placement of echo\/print statements, or correcting plugin\/theme code.<\/span><\/p>\n<h4><span style=\"font-weight: 400;\">Connecting to your site<\/span><\/h4>\n<p><span style=\"font-weight: 400;\">Using an FTP client like FileZilla, connect to your site using the FTP\/SFTP details usually found in your hosting panel. <\/span><\/p>\n<p><span style=\"font-weight: 400;\">For example, 10Web customers can find their SFTP credentials in the dashboard. Head over to Hosting Services &gt; Credentials for everything you need to sign in using an FTP client.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/cannot-modify-header-information-ftp.jpg\" alt=\"Finding the website's SFTP credentials in the 10Web dashboard.\" width=\"1560\" height=\"875\" class=\"alignnone size-full wp-image-27776\" srcset=\"https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/cannot-modify-header-information-ftp.jpg 1560w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/cannot-modify-header-information-ftp-742x416.jpg 742w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/cannot-modify-header-information-ftp-1484x832.jpg 1484w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/cannot-modify-header-information-ftp-150x84.jpg 150w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/cannot-modify-header-information-ftp-768x431.jpg 768w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/cannot-modify-header-information-ftp-1536x862.jpg 1536w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/cannot-modify-header-information-ftp-371x208.jpg 371w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/cannot-modify-header-information-ftp-600x337.jpg 600w\" sizes=\"auto, (max-width: 1560px) 100vw, 1560px\" \/><\/p>\n<p><span style=\"font-weight: 400;\">Navigate to the root directory of your site, which could be named something like `<a href=\"https:\/\/10web.io\/glossary\/public-html\/\">public_html<\/a>`, `public`, or simply your site&#8217;s name. The root of a WordPress folder should look similar to this:<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/wordpress-site-files.jpg\" alt=\"Troubleshooting the cannot modify header information error via FTP.\" width=\"1560\" height=\"875\" class=\"alignnone size-full wp-image-27773\" srcset=\"https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/wordpress-site-files.jpg 1560w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/wordpress-site-files-742x416.jpg 742w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/wordpress-site-files-1484x832.jpg 1484w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/wordpress-site-files-150x84.jpg 150w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/wordpress-site-files-768x431.jpg 768w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/wordpress-site-files-1536x862.jpg 1536w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/wordpress-site-files-371x208.jpg 371w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/wordpress-site-files-600x337.jpg 600w\" sizes=\"auto, (max-width: 1560px) 100vw, 1560px\" \/><\/p>\n<h4><span style=\"font-weight: 400;\">The hunt for the problem file<\/span><\/h4>\n<p><span style=\"font-weight: 400;\">Once you&#8217;re in, it&#8217;s time to play detective. Find the file mentioned in the error message, right-click, and select &#8220;View\/Edit&#8221; to open it in your text editor. This part requires a keen eye; look for the line the error mentioned.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/error-line-number.jpg\" alt=\"The wp-config.php file displayed in a text editor that shows line numbers.\" width=\"1560\" height=\"875\" class=\"alignnone size-full wp-image-27771\" srcset=\"https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/error-line-number.jpg 1560w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/error-line-number-742x416.jpg 742w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/error-line-number-1484x832.jpg 1484w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/error-line-number-150x84.jpg 150w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/error-line-number-768x431.jpg 768w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/error-line-number-1536x862.jpg 1536w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/error-line-number-371x208.jpg 371w, https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/error-line-number-600x337.jpg 600w\" sizes=\"auto, (max-width: 1560px) 100vw, 1560px\" \/><\/p>\n<p><span style=\"font-weight: 400;\">If the issue is not immediately apparent \u2013 say, no obvious whitespaces or lines before the `&lt;?php` tag \u2013 you might need to call in a favor from a PHP-savvy friend. But often, the solution is as simple as removing extra spaces or lines and saving the file.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">After making your edits, save the changes, close your FTP client, and check your site again. With a bit of luck and some careful editing, the error message should be a thing of the past.<\/span><\/p>\n<h2 id=\"wrapping-up\"><span style=\"font-weight: 400;\">Wrapping up<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">While possibly intimidating at first glance, the &#8220;Cannot Modify Header Information&#8221; error is more of a gentle nudge towards meticulous code hygiene than an insurmountable barrier. With the error message serving as a guide, pinpointing and resolving the issue becomes a methodical process. Whether it&#8217;s refining your PHP files, adjusting plugin or theme code, or simply being more mindful of the output sequence, the path to resolution is well within reach.<\/span><br \/>\n \r\n<style>\r\n  #ctablocks_scrollbox-with-icon_89{\r\n            color: #ffffff;\r\n    border-radius: 6px;\r\n  }\r\n\r\n  #ctablocks_scrollbox-with-icon_89 p{\r\n    color: #ffffff;\r\n  }\r\n  #ctablocks_scrollbox-with-icon_89 .button{\r\n          background-color: rgb(51,57,241);\r\n        color: #ffffff;\r\n    border-color: #3339f1 !important;\r\n  }\r\n  #ctablocks_scrollbox-with-icon_89 .button:hover{\r\n    background: rgba(51,57,241,0.8);\r\n    color: #ffffff;\r\n    opacity: 1;\r\n  }\r\n  #ctablocks_scrollbox-with-icon_89.ctablocks_container {\r\n    left: 100%;\r\n  }\r\n  @media screen and (max-width: 1300px) {\r\n      #ctablocks_scrollbox-with-icon_89.ctablocks_container {\r\n          left: 0;\r\n          margin: 0 auto;\r\n      }\r\n  }\r\n  #ctablocks_scrollbox-with-icon_89 .ctablocks_content {\r\n      background-color: #000000;\r\n  }\r\n<\/style>\r\n<div id=\"ctablocks_scrollbox-with-icon_89\" class=\"ctablocks_container scrollbox-with-icon_type\r\n      \">\r\n\r\n  <div class=\"ctablocks_content clear\">\r\n    <div class=\"ctablocks_content_info\">\r\n              <h4>Say goodbye to website errors<\/h4>\r\n        <h4 class=\"mobile-title\">Fix all the website errors in one click<\/h4>\r\n              <p>Migrate your website to the world's best Managed WordPress Hosting.<\/p>\r\n          <\/div>\r\n    <div class=\"ctablocks_content_button\">\r\n              <a href=\"https:\/\/10web.io\/ai-website-builder\/\" class=\"button\" data-gtag=\"sign-up-blog\" data-buttontype=\"sign-up\" data-gtag=\"cta-89\" data-buttontype=\"cta-scrollbox-with-icon\"\r\n\t        >Migrate For Free<\/a>\r\n            \r\n    <\/div>\r\n  <\/div>\r\n    <span class=\"close_ctablocks\">\r\n      <img decoding=\"async\" class=\"close-icon\" src=\"https:\/\/10web.io\/blog\/wp-content\/plugins\/cta-blocks\/assets\/images\/close_w.svg\" class=\"close\">\r\n      <img decoding=\"async\" class=\"floating-icon\" src=\"https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/04\/Info-icon_Blog.png\" alt=\"Say goodbye to website errors\" title=\"Say goodbye to website errors\">\r\n<!--      <img decoding=\"async\" class=\"arrow-icon white\" src=\"\/cta-blocks\/assets\/images\/arrow-icon.svg\" class=\"close\">\r\n-->      <img decoding=\"async\" class=\"arrow-icon purple\" src=\"https:\/\/10web.io\/blog\/wp-content\/plugins\/cta-blocks\/assets\/images\/arrow-icon-purple.svg\" class=\"close\">\r\n  <\/span>\r\n<\/div>\r\n<br \/>\n <\/p>\n","protected":false},"excerpt":{"rendered":"<p>The &#8220;Cannot Modify Header Information \u2013 Headers Already Sent By&#8221; error is one of those classic roadblocks that developers, especially those working with WordPress, encounter from time to time. This error is one such glitch in the matrix that catches many off guard. This error message pops up when your website&#8217;s PHP code has already sent output (like whitespace or&#8230;<\/p>\n","protected":false},"author":39,"featured_media":27775,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"two_page_speed":[],"footnotes":"","tenweb_blog_toc":"                                <ul>\r\n\t<li>\r\n\t\t<a href=\"#understanding-the-culprit-behind-the-curtain\">Understanding the Culprit Behind the Curtain<\/a>\r\n\t<\/li>\r\n\t<li>\r\n\t\t<a href=\"#variations-on-a-theme\">Variations on a Theme<\/a>\r\n\t<\/li>\r\n\t<li>\r\n\t\t<a href=\"#dissecting-the-causes\">Dissecting the Causes<\/a>\r\n\t\t<ul>\r\n\t\t\t<li>\r\n\t\t\t\t<a href=\"#following-the-clues\">Following the clues<\/a>\r\n\t\t\t<\/li>\r\n\t\t<\/ul>\r\n\t<\/li>\r\n\t<li>\r\n\t\t<a href=\"#fixing-the-issue\">Fixing the issue<\/a>\r\n\t\t<ul>\r\n\t\t\t<li>\r\n\t\t\t\t<a href=\"#1-fix-the-error-with-the-plugin-or-theme-editor\">1. Fix the error with the plugin or theme editor<\/a>\r\n\t\t\t<\/li>\r\n\t\t\t<li>\r\n\t\t\t\t<a href=\"#when-in-doubt-reinstall-the-plugin\">When in doubt, reinstall the plugin<\/a>\r\n\t\t\t<\/li>\r\n\t\t\t<li>\r\n\t\t\t\t<a href=\"#2-edit-the-problem-file-via-ftp-sftp\">2. Edit the problem file via FTP\/SFTP<\/a>\r\n\t\t\t<\/li>\r\n\t\t<\/ul>\r\n\t<\/li>\r\n\t<li>\r\n\t\t<a href=\"#wrapping-up\">Wrapping up<\/a>\r\n\t<\/li>\r\n<\/ul>\r\n                        ","tenweb_blog_competitor_type":"","tenweb_blog_competitor_names":"","tenweb_blog_twb_version":0,"tenweb_blog_type":"on"},"categories":[509],"tags":[],"class_list":["post-27772","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-wordpress-errors"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v23.0 (Yoast SEO v23.0) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Fixing the &quot;Cannot Modify Header Information&quot; Error - 10Web<\/title>\n<meta name=\"description\" content=\"Overcome the &quot;Cannot Modify Header Information&quot; PHP error with our expert guide. Learn to troubleshoot and fix in simple steps.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/10web.io\/blog\/cannot-modify-header-information\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Troubleshooting the &quot;Cannot Modify Header Information&quot; Error\" \/>\n<meta property=\"og:description\" content=\"Overcome the &quot;Cannot Modify Header Information&quot; PHP error with our expert guide. Learn to troubleshoot and fix in simple steps.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/10web.io\/blog\/cannot-modify-header-information\/\" \/>\n<meta property=\"og:site_name\" content=\"10Web - Build &amp; Host Your WordPress Website\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/10Web.io\/\" \/>\n<meta property=\"article:published_time\" content=\"2024-03-07T22:38:35+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2024-03-07T22:40:32+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/10web.io\/blog\/wp-content\/uploads\/sites\/2\/2024\/03\/cannot-modify-header-information-featured.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"1792\" \/>\n\t<meta property=\"og:image:height\" content=\"1024\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"Sergey Markosyan\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@10Web_io\" \/>\n<meta name=\"twitter:site\" content=\"@10Web_io\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Sergey Markosyan\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"7 minutes\" \/>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"Fixing the \"Cannot Modify Header Information\" Error - 10Web","description":"Overcome the \"Cannot Modify Header Information\" PHP error with our expert guide. 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