Agent Ready HTML

The Plain Fetch viewer

In short

The viewer requests a URL the way a plain-fetch agent does: no JavaScript, one request for HTML, one for markdown, one for llms.txt and one for a path that should not exist. It shows the initial HTML on the left, the readable text on the right, and seven flags underneath.

Pre-loaded with www.wikipedia.org, read 4 November 2026. Type any public URL to run your own.

GET https://react.dev/ answered 200 with text/html, 266 KB, read 8 November 2026, 13:08 UTC.

Permalink: /viewer/?url=https://react.dev/

The page answers a plain fetch: 3 of 6 checks found.

Initial HTML what a plain fetch receives

<!DOCTYPE html>
<html lang="en" dir="ltr">
<head>
<meta charSet="utf-8" data-next-head=""/>
<meta name="viewport" content="width=device-width, initial-scale=1" data-next-head=""/>
[... 1 more head element folded ...]
<title data-next-head="">React
</title>
<meta name="description" content="React is the library for web and native user interfaces. Build user interfaces out of individual pieces called components written in JavaScript. React is designed to let you seamlessly c [... 95 characters folded ...]>
<link rel="canonical" href="https://react.dev/" data-next-head=""/>
<link rel="alternate" href="https://react.dev/" hrefLang="x-default" data-next-head=""/>
<link rel="alternate" hrefLang="en" href="https://react.dev/" data-next-head=""/>
<link rel="alternate" hrefLang="zh-hans" href="https://zh-hans.react.dev/" data-next-head=""/>
<link rel="alternate" hrefLang="es" href="https://es.react.dev/" data-next-head=""/>
<link rel="alternate" hrefLang="fr" href="https://fr.react.dev/" data-next-head=""/>
<link rel="alternate" hrefLang="ja" href="https://ja.react.dev/" data-next-head=""/>
<link rel="alternate" hrefLang="tr" href="https://tr.react.dev/" data-next-head=""/>
<link rel="alternate" hrefLang="ko" href="https://ko.react.dev/" data-next-head=""/>
[... 22 more head elements folded ...]
<link rel="alternate" type="application/rss+xml" title="React Blog RSS Feed" href="/rss.xml" data-next-head=""/>
[... 22 more head elements folded ...]
</head>
<script>[... 139 characters folded ...]
</script>
<body class="font-text font-medium antialiased text-lg bg-wash dark:bg-wash-dark text-secondary dark:text-secondary-dark leading-base">
<script>[... 2,168 characters folded ...]
</script>
<script>[... 1,875 characters folded ...]
</script>
<link rel="preload" as="image" imageSrcSet="/_next/image?url=%2Fimages%2Fuwu.png&amp;w=64&amp;q=75 1x, /_next/image?url=%2Fimages%2Fuwu.png&amp;w=128&amp;q=75 2x"/>
<link rel="preload" as="image" imageSrcSet="/_next/image?url=%2Fimages%2Fuwu.png&amp;w=384&amp;q=75 1x, /_next/image?url=%2Fimages%2Fuwu.png&amp;w=640&amp;q=75 2x"/>
<link rel="preload" as="image" href="/images/uwu.png"/>
<link rel="preload" as="image" href="/images/home/conf2021/cover.svg"/>
<link rel="preload" as="image" href="/images/home/conf2021/andrew.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/lauren.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/juan.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/rick.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/shruti.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/shaundai.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/aakansha.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/brian.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/xuan.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/rachel.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/debbie.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/sarah.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/linton.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/delba.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/robert.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/eric.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/steven.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/roman.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/daishi.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/diego.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/tafu.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/lyle.jpg"/>
<link rel="preload" as="image" href="/images/home/conf2021/helen.jpg"/>
<link rel="preload" href="/images/home/conf2019/cover.svg" as="image"/>
<link rel="preload" href="/images/home/conf2021/cover.svg" as="image"/>
<div id="__next">
<div>
</div>
<div class="z-40 sticky top-0">
<nav class="duration-300 backdrop-filter backdrop-blur-lg backdrop-saturate-200 transition-shadow bg-opacity-90 items-center w-full flex justify-between bg-wash dark:bg-wash-dark dark:bg-opacity-95 px-1.5 lg:pe-5 lg:ps-4 z-40">
<div class="flex items-center justify-between w-full h-16 gap-0 sm:gap-3">
<div class="flex flex-row 3xl:flex-1 items-centers"><button type="button" aria-label="Menu" class="active:scale-95 transition-transform flex lg:hidden w-12 h-12 rounded-full items-center justify-center hover:bg-primary/5 hover:dark:bg-primary-dark/5 outline-link">
<svg width="1.33em" height="1.33em" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">[... 130 characters folded ...]
</svg></button><span data-state="closed" class="flex items-center" style="-webkit-touch-callout:none">
<div class="flex items-center">
<div class="uwu-visible flex items-center justify-center h-full"><a class="active:scale-95 transition-transform" href="/"><img alt="logo by @sawaratsuki1004" title="logo by @sawaratsuki1004" width="63" height="32" decoding="async" data-nimg="1" class="h-8" style="color:transparent" srcSet="/_next/image?url=%2Fimages%2Fuwu.png&amp;w=64&amp;q [... 131 characters folded ...]></a>
</div>
<div class="uwu-hidden"><a class="active:scale-95 overflow-hidden transition-transform relative items-center text-primary dark:text-primary-dark p-1 whitespace-nowrap outline-link rounded-full 3xl:rounded-xl inline-flex text-lg font-normal gap-2" href="/">
<svg width="100%" height="100%" viewBox="-10.5 -9.45 21 18.9" fill="none" xmlns="http://www.w3.org/2000/svg" class="text-sm me-0 w-10 h-10 text-brand dark:text-brand-dark flex origin-center transition-all ease-in-out">[... 270 characters folded ...]
</svg><span class="sr-only 3xl:not-sr-only">React</span></a>
</div>
</div></span>
<div class="flex flex-column justify-center items-center"><a class=" flex py-2 flex-column justify-center items-center text-gray-50 dark:text-gray-30 hover:text-link hover:dark:text-link-dark hover:underline text-sm ms-1 cursor-pointer" href="/versions">v<!-- -->19.3</a>
</div>
</div>
<div class="items-center justify-center flex-1 hidden w-full md:flex 3xl:w-auto 3xl:shrink-0 3xl:justify-center"><button type="button" class="flex 3xl:w-[56rem] 3xl:mx-0 relative ps-4 pe-1 py-1 h-10 bg-gray-30/20 dark:bg-gray-40/20 outline-none focus:outline-link betterhover:hover:bg-opacity-80 pointer items-center text-start w-full text-gray-30 rounded-full align-middle text-base">
<svg width="1em" height="1em" viewBox="0 0 20 20" class="align-middle me-3 text-gray-30 shrink-0 group-betterhover:hover:text-gray-70">[... 332 characters folded ...]
</svg>Search<span class="hidden ms-auto sm:flex item-center me-1"><kbd class="w-5 h-5 border border-transparent me-1 bg-wash dark:bg-wash-dark text-gray-30 align-middle p-0 inline-flex justify-center items-center text-xs text-center rounded-md" data-platform="mac">⌘</kbd><kbd class="w-10 h-5 border border-transparent me-1 bg-wash dark:bg-wash-dark text-gray-30 align-middle p-0 inline-flex justify-center items-center text-xs text-center rounded-md" data-platform="win">Ctrl</kbd><kbd class="w-5 h-5 border border-transparent me-1 bg-wash dark:bg-wash-dark text-gray-30 align-middle p-0 inline-flex justify-center items-center text-xs text-center rounded-md">K</kbd></span></button>
</div>
<div class="text-base justify-center items-center gap-1.5 flex 3xl:flex-1 flex-row 3xl:justify-end">
<div class="mx-2.5 gap-1.5 hidden lg:flex">
<div class="flex flex-auto sm:flex-1"><a class="active:scale-95 transition-transform w-full text-center outline-link py-1.5 px-1.5 xs:px-3 sm:px-4 rounded-full capitalize whitespace-nowrap hover:bg-primary/5 hover:dark:bg-primary-dark/5" href="/learn">Learn</a>
</div>
<div class="flex flex-auto sm:flex-1"><a class="active:scale-95 transition-transform w-full text-center outline-link py-1.5 px-1.5 xs:px-3 sm:px-4 rounded-full capitalize whitespace-nowrap hover:bg-primary/5 hover:dark:bg-primary-dark/5" href="/reference/react">Reference</a>
</div>
<div class="flex flex-auto sm:flex-1"><a class="active:scale-95 transition-transform w-full text-center outline-link py-1.5 px-1.5 xs:px-3 sm:px-4 rounded-full capitalize whitespace-nowrap hover:bg-primary/5 hover:dark:bg-primary-dark/5" href="/community">Community</a>
</div>
<div class="flex flex-auto sm:flex-1"><a class="active:scale-95 transition-transform w-full text-center outline-link py-1.5 px-1.5 xs:px-3 sm:px-4 rounded-full capitalize whitespace-nowrap hover:bg-primary/5 hover:dark:bg-primary-dark/5" href="/blog">Blog</a>
</div>
</div>
<div class="flex w-full md:hidden">
</div>
<div class="flex items-center -space-x-2.5 xs:space-x-0 ">
<div class="flex md:hidden"><button aria-label="Search" type="button" class="flex items-center justify-center w-12 h-12 transition-transform rounded-full active:scale-95 md:hidden hover:bg-secondary-button hover:dark:bg-secondary-button-dark outline-link">
<svg width="1em" height="1em" viewBox="0 0 20 20" class="w-5 h-5 align-middle">[... 332 characters folded ...]
</svg></button>
</div>
<div class="flex dark:hidden"><button type="button" aria-label="Use Dark Mode" class="flex items-center justify-center w-12 h-12 transition-transform rounded-full active:scale-95 hover:bg-primary/5 hover:dark:bg-primary-dark/5 outline-link">
<svg xmlns="http://www.w3.org/2000/svg" width="28" height="28" viewBox="0 0 32 32">[... 1,031 characters folded ...]
</svg></button>
</div>
<div class="hidden dark:flex"><button type="button" aria-label="Use Light Mode" class="flex items-center justify-center w-12 h-12 transition-transform rounded-full active:scale-95 hover:bg-primary/5 hover:dark:bg-primary-dark/5 outline-link">
<svg xmlns="http://www.w3.org/2000/svg" width="32" height="32" viewBox="0 0 32 32">[... 4,522 characters folded ...]
</svg></button>
</div>
<div class="flex"><a class="active:scale-95 transition-transform flex w-12 h-12 rounded-full items-center justify-center hover:bg-primary/5 hover:dark:bg-primary-dark/5 outline-link" aria-label="Translations" href="/community/translations">
<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24">[... 336 characters folded ...]
</svg></a>
</div>
<div class="flex"><a class="flex items-center justify-center w-12 h-12 transition-transform rounded-full active:scale-95 hover:bg-primary/5 hover:dark:bg-primary-dark/5 outline-link" target="_blank" rel="noreferrer noopener" aria-label="Open on GitHub" href="https://github.com/react/react/releases">
<svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24">[... 758 characters folded ...]
</svg></a>
</div>
</div>
</div>
</div>
</nav>
</div>
<div class=""><!--$-->
<main class="min-w-0 isolate">
<article class="font-normal break-words text-primary dark:text-primary-dark">
<div class="ps-0">
<div class="mx-5 mt-12 lg:mt-24 mb-20 lg:mb-32 flex flex-col justify-center">
<div class="uwu-visible flex justify-center"><img alt="logo by @sawaratsuki1004" title="logo by @sawaratsuki1004" loading="eager" width="313" height="160" decoding="async" data-nimg="1" style="color:transparent" srcSet="/_next/image?url=%2Fimages%2Fuwu.png&amp;w=38 [... 138 characters folded ...]>
</div>
<svg width="100%" height="100%" viewBox="-10.5 -9.45 21 18.9" fill="none" xmlns="http://www.w3.org/2000/svg" class="uwu-hidden mt-4 mb-3 text-brand dark:text-brand-dark w-24 lg:w-28 self-center text-sm me-0 flex origin-center transition-all ease-in-out">[... 270 characters folded ...]
</svg>
<h1 class="uwu-hidden text-5xl font-display lg:text-6xl self-center flex font-semibold leading-snug text-primary dark:text-primary-dark">React
</h1>
<p class="text-4xl font-display max-w-lg md:max-w-full py-1 text-center text-secondary dark:text-primary-dark leading-snug self-center">The library for web and native user interfaces
</p>
<div class="mt-5 self-center flex gap-2 w-full sm:w-auto flex-col sm:flex-row"><a class="w-full sm:w-auto justify-center active:scale-[.98] transition-transform inline-flex font-bold items-center outline-none focus:outline-none focus-visible:outline focus-visible:outline-link focus:outline-offset-2 [... 227 characters folded ...]>Learn React</a><a class="w-full sm:w-auto justify-center active:scale-[.98] transition-transform inline-flex font-bold items-center outline-none focus:outline-none focus-visible:outline focus-visible:outline-link focus:outline-offset-2 [... 361 characters folded ...]>API Reference</a>
</div>
</div>
<div class="mx-auto flex flex-col w-full bg-gradient-left dark:bg-gradient-left-dark border-t border-primary/10 dark:border-primary-dark/10 " style="contain:content">
<div class="flex-col gap-2 flex grow w-full my-20 lg:my-32 mx-auto items-center">
<div class="px-5 lg:px-0 max-w-4xl lg:text-center text-white text-opacity-80 flex flex-col items-center justify-center">

Shown with 208 long blocks (scripts, styles, long tags) folded into a marker that says how many characters they hide; line breaks added before block tags because the source is minified; the pane stops after the first 200 words; the page is 266 KB.

Reading view the text a plain-fetch client can extract

title: React

React

React v 19.3 Search⌘CtrlK Learn Reference Community Blog React The library for web and native user interfaces Learn React API Reference Create user interfaces from components React lets you build user interfaces out of individual pieces called components. Create your own React components like Thumbnail, LikeButton, and Video. Then combine them into entire screens, pages, and apps. Video.js function Video({ video }) { return ( <div> <Thumbnail video={video} /> <a href={video.url}> <h3>{video.title}</h3> <p>{video.description}</p> </a> <LikeButton video={video} /> </div> ); } My video Video description Whether you work on your own or with thousands of other developers, using React feels the same. It is designed to let you seamlessly combine components written by independent people, teams, and organizations. Write components with code and markup React components are JavaScript functions. Want to show some content conditionally? Use an if statement. Displaying a list? Try array map(). Learning React is learning programming. VideoList.js function VideoList({ videos, emptyHeading }) { const count = videos.length; let heading = emptyHeading; if (count > 0) { const noun = count > 1 ? 'Videos' : 'Video'; heading = count + ' ' + noun; } return ( <section> <h2>{heading}</h2> {videos.map(video => <Video key={video.id} video={video} /> )} </section>

1029 more words follow in the initial HTML.

3 found, 2 missing, 2 notes, from 7 checks run

  • H1Found
  • 200 wordsFound
  • llms.txtNote
  • MarkdownMissing
  • Missing pathFound
  • JSON-LDMissing
  • OpenAPINote
What a plain fetch found on react.dev
CheckResultDetail
H1 in the initial HTMLFound 2 H1 elementsFirst H1: React
First 200 words in the initial HTMLFound 200 of 200 wordsThe initial HTML carries 1229 words of visible text; the first 200 are marked in the left pane.
llms.txt present and linkedNote present, not linked14571 bytes, 180 links. Structure grade A (6 of 6). Nothing on the home page points to it. Ora's lab found 86 percent of llms.txt fetches arrived through a link.
Markdown on requestMissing 404 text/htmlAccept: text/markdown returned 404 with text/html; charset=utf-8. The server ignores the header.
Status of a made-up pathFound 404/agent-ready-html-missing-path-check returned 404: a real status code for a missing page.
JSON-LD typesMissing noneNo JSON-LD block on the home page. Ora's lab found it made no difference when the answer was already in the HTML; Google says it is not needed for AI features.
OpenAPI linkNote none on the home pageNo OpenAPI link on the home page. It matters only for a site that ships an API.

Run the full check

The viewer read one page with four requests. The full check we recommend next is Ora's scan. Its Access layer runs 42 checks worth 30 of its 100 points, among them content without JavaScript, bot detection, llms.txt, markdown on request, JSON-LD and the sitemap (Ora's check catalogue, contract 1.38.0, read 5 November 2026). Open Ora's report for react.dev.

Limits: Ora reads public URLs only, says two runs of one scan land within a couple of points without publishing repeat-scan data, and keeps the product that fixes what it finds behind a waitlist. Cloudflare's scanner at isitagentready.com is a quick free alternative, and Mintlify's score covers documentation.

What the viewer does

It sends four plain GET requests with the user agent Mozilla/5.0 (compatible; agent-readiness-crawl/1.0): the URL itself, the same URL with Accept: text/markdown, /llms.txt on the same host, and a made-up path at the root. It runs no JavaScript. The left pane is the first bytes of the HTML as text, with long scripts and styles folded into a marker that says how many characters they hide. The H1 and the first 200 words of visible text are marked in both panes. The flags under the panes say what the four responses added up to.

Limits

  • Ten seconds for all four requests together, 1.5 MB read from the home page, at most five redirects, each one checked again.
  • http and https only, default ports only. Private, local and internal addresses and names are refused.
  • Ten runs per address per minute. The counter lives in memory on the edge function, so it is per instance rather than global. Past ten you get a 429 with a Retry-After header.
  • Results are cached for 24 hours by the response headers. Nothing is written to a database: the viewer keeps the first 200 words and the extracted fields for the length of the request and keeps no page body beyond that.

What it does not tell you

A plain fetch from this server is not a real agent. Bot protection weighs the source address more than the user agent, so a page that answers 200 here can still refuse an agent, and the reverse. Ora's lab found (2026-10-19) that returning 403 to agent user agents and hiding the answer in JavaScript were the only two of 19 configurations that stopped retrieval; the viewer can see the second, and can only hint at the first. The initial HTML reference covers both. The server logs and the published crawler address ranges settle the first.

The seven flags

H1 in the initial HTML
Whether the HTML the server sends already contains an H1. It is the cheapest sign that the page does not depend on scripts to say what it is.
First 200 words in the initial HTML
Whether at least 200 words of visible text arrive in the initial HTML. Under 40 words with an app root element is flagged as a JavaScript shell.
llms.txt present and linked
Whether /llms.txt answers with a plain-text file, whether the home page links it (an anchor, a link element or a Link header), and the structure grade the index uses.
Markdown on request
Whether a request with Accept: text/markdown comes back as text/markdown. Cloudflare Radar found 3.9 percent of scanned top sites passing this at its April 2026 launch.
Status of a made-up path
Whether a path that should not exist returns 404 or 410. A 200 is a soft 404 and reads as a live page.
JSON-LD types
The schema.org types found in JSON-LD blocks on the page. Ora's lab found JSON-LD made no difference when the answer was already in the HTML.
OpenAPI link
Whether the page links an OpenAPI file, by an anchor or a service-desc link relation. It matters only for a site that ships an API.

Sources

  1. Ora: AgentReady launch post (Ora's lab findings) https://ora.ai/blog/agentready-launch, read 4 November 2026
  2. Ora check catalogue, contract 1.38.0 (132 checks, 42 in the Access layer) https://ora.ai/api/checks, read 5 November 2026
  3. Ora home page (the fixing product is behind a waitlist) https://ora.ai/, read 5 November 2026
  4. Ora: Introducing Deep Scan (repeat scans) https://ora.ai/blog/introducing-deep-scan, read 5 November 2026
  5. Ora llms.txt (public URLs only) https://ora.ai/llms.txt, read 5 November 2026
  6. Vercel: Make your site readable by AI agents https://vercel.com/kb/guide/make-your-site-readable-by-ai-agents, read 4 November 2026
  7. llms.txt proposal (llmstxt.org) https://llmstxt.org/, read 4 November 2026

Last reviewed 5 November 2026