--- title: You're using a too-old browser | daily.dev description: A personal blog and wiki operator explains an error page shown to visitors flagged by anti-crawler defenses that block suspicious or outdated browser... canonical: https://daily.dev/posts/you-re-using-a-too-old-browser-5lr6pttqb twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: You're using a too-old browser | daily.dev og:description: A personal blog and wiki operator explains an error page shown to visitors flagged by anti-crawler defenses that block suspicious or outdated browser... og:url: https://daily.dev/posts/you-re-using-a-too-old-browser-5lr6pttqb og:image: https://api.daily.dev/og/posts/5lR6Pttqb.png og:image:alt: You're using a too-old browser og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # You're using a too-old browser **[Planet Golang](https://daily.dev/sources/planetgolang)** · 3 min read · 1 upvotes · 0 comments ## Summary A personal blog and wiki operator explains an error page shown to visitors flagged by anti-crawler defenses that block suspicious or outdated browser User-Agent strings, particularly old Chrome versions widely used by high-volume crawlers (some scraping data for LLM training). The page details known false positives: Inoreader and Feedly feed fetchers mistakenly using fake old-browser User-Agents, Vivaldi users needing to disable Chrome User-Agent brand masking, and archive.today/archive.ph crawlers using suspicious old Chrome UAs and spoofed reverse DNS. Users are advised to use archive.org instead and to contact the site owner if incorrectly blocked. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### Why does Vivaldi need User Agent Brand Masking disabled to avoid being blocked as an old browser? Vivaldi's User Agent Brand Masking setting makes it identify itself as Google Chrome rather than Vivaldi in the User-Agent string. Because a wave of high-volume crawlers spoof old Chrome User-Agent values, sites running anti-crawler blocking can mistakenly flag genuine Vivaldi users; disabling the setting so Vivaldi reports itself honestly avoids getting caught by that filtering, even on the current Vivaldi version. _daily.dev readers troubleshooting browser fingerprinting and bot-blocking issues can dig into cases like this one._ ### Why do RSS readers like Inoreader and Feedly sometimes show visitors an error page instead of the actual feed content? Some feed readers periodically fetch feeds using a fake, old-browser HTTP User-Agent header, which gets blocked by anti-crawler defenses; when that fetch fails, the reader mistakenly caches the resulting error page and serves it to users instead of the real syndication feed content, and there is no fix available from the site owner's side, only from the feed reader vendor. _developers debugging feed-fetching or User-Agent-dependent HTTP behavior can compare notes like this on daily.dev._ ## Similar posts on daily.dev - [Serious editors are a commitment \(at least for me\)](https://daily.dev/posts/serious-editors-are-a-commitment-at-least-for-me--0dokaupm6) · Lobsters · 0 upvotes · 0 comments - [Browser fingerprint tool shows how easy you are to track using the latest sneaky tricks](https://daily.dev/posts/browser-fingerprint-tool-shows-how-easy-you-are-to-track-using-the-latest-sneaky-tricks-wxysgwoy3) · The Register · 0 upvotes · 0 comments - [News Sites Are Blocking Internet Archive Over AI Scraping Fears](https://daily.dev/posts/news-sites-are-blocking-internet-archive-over-ai-scraping-fears-2mqqvfze1) · Hackaday · 0 upvotes · 0 comments - [News publishers limit Internet Archive access due to AI scraping concerns](https://daily.dev/posts/news-publishers-limit-internet-archive-access-due-to-ai-scraping-concerns-pfgxshyte) · Hacker News · 2 upvotes · 0 comments --- [View this post on daily.dev](https://daily.dev/posts/you-re-using-a-too-old-browser-5lr6pttqb) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"You're using a too-old browser","url":"https://daily.dev/posts/you-re-using-a-too-old-browser-5lr6pttqb","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/you-re-using-a-too-old-browser-5lr6pttqb"},"datePublished":"2026-08-18T11:46:38.817Z","dateModified":"2026-09-14T06:18:47.490Z","description":"A personal blog and wiki operator explains an error page shown to visitors flagged by anti-crawler defenses that block suspicious or outdated browser...","image":"https://media.daily.dev/image/upload/s--HRgLpUt6--/f_auto/v1722860399/public/Placeholder%2003","thumbnailUrl":"https://media.daily.dev/image/upload/s--HRgLpUt6--/f_auto/v1722860399/public/Placeholder%2003","isAccessibleForFree":true,"articleSection":"Planet Golang","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Planet Golang","logo":"https://media.daily.dev/image/upload/s--nkaYE8PY--/f_auto/v1721572510/logos/planetgolang","url":"https://daily.dev/sources/planetgolang"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/you-re-using-a-too-old-browser-5lr6pttqb","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":1},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"","timeRequired":"PT3M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Planet Golang","item":"https://daily.dev/sources/planetgolang"},{"@type":"ListItem","position":3,"name":"You're using a too-old browser"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/you-re-using-a-too-old-browser-5lr6pttqb#faq","mainEntity":[{"@type":"Question","name":"Why does Vivaldi need User Agent Brand Masking disabled to avoid being blocked as an old browser?","acceptedAnswer":{"@type":"Answer","text":"Vivaldi's User Agent Brand Masking setting makes it identify itself as Google Chrome rather than Vivaldi in the User-Agent string. Because a wave of high-volume crawlers spoof old Chrome User-Agent values, sites running anti-crawler blocking can mistakenly flag genuine Vivaldi users; disabling the setting so Vivaldi reports itself honestly avoids getting caught by that filtering, even on the current Vivaldi version. daily.dev readers troubleshooting browser fingerprinting and bot-blocking issues can dig into cases like this one."}},{"@type":"Question","name":"Why do RSS readers like Inoreader and Feedly sometimes show visitors an error page instead of the actual feed content?","acceptedAnswer":{"@type":"Answer","text":"Some feed readers periodically fetch feeds using a fake, old-browser HTTP User-Agent header, which gets blocked by anti-crawler defenses; when that fetch fails, the reader mistakenly caches the resulting error page and serves it to users instead of the real syndication feed content, and there is no fix available from the site owner's side, only from the feed reader vendor. developers debugging feed-fetching or User-Agent-dependent HTTP behavior can compare notes like this on daily.dev."}}]} ```