{"id":2354,"date":"2025-04-29T14:35:45","date_gmt":"2025-04-29T14:35:45","guid":{"rendered":"https:\/\/odyseo.pl\/?p=2354"},"modified":"2025-04-29T14:35:45","modified_gmt":"2025-04-29T14:35:45","slug":"error-400-what-does-it-mean-and-how-to-fix-it","status":"publish","type":"post","link":"https:\/\/odyseo.pl\/en\/blog\/blad-400-co-oznacza-i-jak-go-naprawic\/","title":{"rendered":"Error 400 - what does it mean and how do I fix it?"},"content":{"rendered":"<p>Error 400 is a common hassle that can be encountered when surfing the web. It can negatively affect both the user experience and SEO. We take a closer look at what this error is, its sources and how to fix it to improve your website's performance. <strong>Find out how to effectively deal with error 400 and why fixing it is key to improving your website's online visibility.<\/strong><\/p>\n<h2>What is error 400?<\/h2>\n<p><strong>Error 400<\/strong>, known as <strong>Bad Request<\/strong>, is an HTTP message indicating that the server is having difficulty processing the request. It indicates that the server is having trouble interpreting the data received from the client, which is often due to incorrect formatting of the information. For example, the browser may send something that the server considers to be incorrect.<\/p>\n<p>Other causes of this error include:<\/p>\n<ul>\n<li>Incorrect HTTP requests,<\/li>\n<li>incomplete data,<\/li>\n<li>use of inappropriate request methods.<\/li>\n<\/ul>\n<p><strong>For users, this means not being able to load the expected page, which is frustrating and negatively affects their experience.<\/strong> To solve this problem, it is often necessary to correct the formatting of the request so that the server can interpret it correctly.<\/p>\n<h2>Causes of error 400<\/h2>\n<p><strong>Error 400<\/strong>, i.e. <strong>Bad Request<\/strong>, occurs when the server is unable to interpret the request correctly. This is most often due to:<\/p>\n<ul>\n<li>incorrectly constructed URL,<\/li>\n<li>invalid cookies,<\/li>\n<li>bad data coding,<\/li>\n<li>incorrectly configured headers, especially those related to authorisation.<\/li>\n<li>using the wrong method, e.g. POST instead of GET,<\/li>\n<li>exceeding the permitted file size.<\/li>\n<\/ul>\n<p>These errors make it difficult for the server to understand the client's intentions. <strong>Invalid cookies complicate the authorisation process by transmitting incorrect information.<\/strong><\/p>\n<p>In addition, network errors, such as incorrect URL interpretations, can lead to such problems. To avoid them, it is worth ensuring that all elements of the request are correctly worded and in line with the server's requirements.<\/p>\n<h2>How to fix error 400?<\/h2>\n<p>To deal with error 400, first make sure that the URL is properly formatted. Sometimes minor mistakes in the address are a source of trouble. Next, try clearing cookies and the browser cache, which often helps to get rid of locally stored, outdated data. Also check that request headers meet format requirements and are within acceptable size limits.<\/p>\n<p><strong>Updating the browser and its plug-ins can also improve compatibility with modern web standards, which may help to solve the problem.<\/strong> Additionally, refreshing the page and clearing the DNS cache may prove effective. If the problem persists, it is worth examining the HTTP requests in detail to identify possible errors in their design.<\/p>\n<h2>Impact of Error 400 on SEO and user experience<\/h2>\n<p>Error <strong>400<\/strong>, known as <strong>Bad Request<\/strong>, can have a major impact on <strong>SEO<\/strong> and user experience. When visitors encounter this problem, they often leave the site quickly, leading to an increase in the rejection rate. <strong>This, in turn, suggests to search engine algorithms that the site may be suffering from content or functionality issues, which adversely affects its positioning.<\/strong><\/p>\n<p>However, this is not the only challenge. Errors 400 can also prevent search engine robots from effectively indexing a page. If these have difficulty indexing the site due to errors, its visibility in search results drops, which reduces organic traffic. In addition, such problems can undermine users' trust in the site, with the associated loss of potential customers.<\/p>\n<p>In order to minimise the negative effects of Error 400, regular monitoring and rapid elimination of problems is essential. <strong>A well-optimised site, with as few technical errors as possible, promotes a positive user experience and better SEO results.<\/strong><\/p>","protected":false},"excerpt":{"rendered":"<p>B\u0142\u0105d 400 to powszechny k\u0142opot, na kt\u00f3ry mo\u017cna natkn\u0105\u0107 si\u0119 podczas surfowania po sieci. Mo\u017ce on negatywnie wp\u0142ywa\u0107 zar\u00f3wno na wra\u017cenia u\u017cytkownik\u00f3w, jak i na SEO. Przybli\u017camy, czym jest ten b\u0142\u0105d, jakie s\u0105 jego \u017ar\u00f3d\u0142a i jak go usun\u0105\u0107, aby usprawni\u0107 dzia\u0142anie strony internetowej. Sprawd\u017a, jak skutecznie radzi\u0107 sobie z b\u0142\u0119dem 400 oraz dlaczego jego&#8230;<\/p>","protected":false},"author":2,"featured_media":2486,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_kad_blocks_custom_css":"","_kad_blocks_head_custom_js":"","_kad_blocks_body_custom_js":"","_kad_blocks_footer_custom_js":"","_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"_kad_post_classname":"","footnotes":""},"categories":[20],"tags":[],"class_list":["post-2354","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-techniczne-seo"],"acf":[],"taxonomy_info":{"category":[{"value":20,"label":"Techniczne SEO"}]},"featured_image_src_large":["https:\/\/odyseo.pl\/wp-content\/uploads\/2025\/04\/laptop-5906264_1280-1024x634.png",1024,634,true],"author_info":{"display_name":"Micha\u0142 Woroniecki","author_link":"https:\/\/odyseo.pl\/en\/author\/michal\/"},"comment_info":1,"category_info":[{"term_id":20,"name":"Techniczne SEO","slug":"techniczne-seo","term_group":0,"term_taxonomy_id":20,"taxonomy":"category","description":"","parent":0,"count":6,"filter":"raw","cat_ID":20,"category_count":6,"category_description":"","cat_name":"Techniczne SEO","category_nicename":"techniczne-seo","category_parent":0}],"tag_info":false,"_links":{"self":[{"href":"https:\/\/odyseo.pl\/en\/wp-json\/wp\/v2\/posts\/2354","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/odyseo.pl\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/odyseo.pl\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/odyseo.pl\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/odyseo.pl\/en\/wp-json\/wp\/v2\/comments?post=2354"}],"version-history":[{"count":0,"href":"https:\/\/odyseo.pl\/en\/wp-json\/wp\/v2\/posts\/2354\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/odyseo.pl\/en\/wp-json\/wp\/v2\/media\/2486"}],"wp:attachment":[{"href":"https:\/\/odyseo.pl\/en\/wp-json\/wp\/v2\/media?parent=2354"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/odyseo.pl\/en\/wp-json\/wp\/v2\/categories?post=2354"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/odyseo.pl\/en\/wp-json\/wp\/v2\/tags?post=2354"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}