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.
The page answers a plain fetch: 5 of 6 checks found.
Initial HTML what a plain fetch receives
<!DOCTYPE html>
<html lang="en">
<head>
[... 1 more head element folded ...]
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1">
[... 2 more head elements folded ...]
<meta name="generator" content="Astro v7.3.1">
[... 4 more head elements folded ...]
<link rel="canonical" href="https://developers.openai.com/">
[... 1 more head element folded ...]
<title data-default-meta-title="OpenAI Developers">
OpenAI Developers
</title>
[... 1 more head element folded ...]
<meta name="description" content="Docs and resources to help you build with, for, and on OpenAI.">
[... 18 more head elements folded ...]
<link rel="sitemap" href="/sitemap-index.xml">
[... 1 more head element folded ...]
<link rel="alternate" type="application/rss+xml" title="OpenAI Developers" data-page-meta-title href="https://developers.openai.com/rss.xml">
[... 10 more head elements folded ...]
</head>
<body class="overflow-x-hidden">
<div class="agent-docs-directive" data-agent-docs-directive data-astro-cid-q6irbmzd>
For the complete documentation index, see <a href="/llms.txt" tabindex="-1" data-astro-cid-q6irbmzd>llms.txt</a>. Markdown versions of documentation pages are available by appending
<code data-astro-cid-q6irbmzd>.md</code> to the page URL.
</div>
<script type="module" src="/_astro/Header.astro_astro_type_script_index_0_lang.B2pN_4rK.js?dpl=dpl_ABYczWiLJFWvyg1JeJiu2e8rRdgG">
</script>
<header id="header" class="fixed top-0 w-full h-16 z-50 bg-white dark:bg-black border-b border-primary-surface">
<div class="flex h-full items-center px-4 md:px-8 lg:grid lg:grid-cols-[minmax(0,1fr)_auto_minmax(0,1fr)] lg:gap-6"> <!-- Logo --> <a href="/" class="order-1 ml-0 flex min-h-11 min-w-11 items-center justify-center font-semibold lg:col-start-1 lg:row-start-1 lg:-ml-2 lg:justify-self-start"> <img src="/OpenAI_Developers.svg" alt="OpenAI Developers" class="h-6 w-48 md:h-6 dark:invert" data-site-visibility-exclude="chatgpt-docs"> <span class="flex items-center text-default" data-site-visibility-include="chatgpt-docs">
<svg width="1em" height="1em" viewBox="100 100 411 411" fill="none" xmlns="http://www.w3.org/2000/svg" class="h-6 w-6" aria-hidden="true">[... 2,335 characters folded ...]
</svg> <span class="sr-only">ChatGPT</span> </span> </a> <!-- Theme Toggle, Mobile Menu -->
<div class="order-2 ml-auto flex shrink-0 items-center gap-4 md:gap-3 lg:col-start-3 lg:row-start-1 lg:ml-0 lg:justify-end lg:justify-self-end lg:gap-5"> <button type="button" data-header-search-button aria-controls="header-search-overlay" aria-expanded="false" class="order-1 hidden min-w-52 items-center justify-between gap-3 rounded-full border border-primary-surface bg- [... 116 characters folded ...]> <span class="truncate">Start searching</span>
<svg width="1em" height="1em" viewBox="0 0 24 24" fill="currentColor" class="h-4 w-4 shrink-0">[... 578 characters folded ...]
</svg> </button>
<div class="order-2 hidden lg:flex">
<div data-site-visibility-exclude="chatgpt-docs">
<div class="flex items-center gap-2"><a target="_blank" rel="noopener noreferrer" href="https://platform.openai.com/login" class="_Button_6dmow_1 not-prose !h-9 !w-9 justify-center !px-0 min-[1000px]:!w-auto min-[1000px]:!px-4" data-color="primary" data-variant="solid" data-pill="" data-size="md"><span class="_ButtonInner_6dmow_4"><span class="sr-only min-[1000px]:not-sr-only">API Dashboard</span>
<svg width="1em" height="1em" viewBox="0 0 24 24" fill="currentColor" data-external-link-indicator="persistent" class="shrink-0">[... 184 characters folded ...]
</svg></span></a>
</div>
</div>
<div data-site-visibility-include="chatgpt-docs">
<div class="flex items-center gap-2"><a target="_blank" rel="noopener noreferrer" href="https://chatgpt.com/" class="_Button_6dmow_1 not-prose !w-9 justify-center !px-0 min-[1000px]:!w-auto min-[1000px]:!px-4" data-color="primary" data-variant="solid" data-pill="" data-size="lg"><span class="_ButtonInner_6dmow_4"><span class="sr-only min-[1000px]:not-sr-only">Try ChatGPT</span>
<svg width="1em" height="1em" viewBox="0 0 24 24" fill="currentColor" data-external-link-indicator="persistent" class="shrink-0">[... 184 characters folded ...]
</svg></span></a>
</div>
</div>
</div> <details data-theme-picker name="theme-picker" class="relative shrink-0 order-4 hidden lg:block"> <summary id="header-theme-button" role="button" aria-label="Choose theme" title="Choose theme" aria-controls="header-theme-button-choices" class="flex h-11 w-11 cursor-pointer list-none items-center justify-center rounde [... 242 characters folded ...]>
<svg width="1em" height="1em" viewBox="0 0 24 24" fill="currentColor" class="block dark:hidden w-4 h-4" aria-hidden="true">[... 1,728 characters folded ...]
</svg>
<svg width="1em" height="1em" viewBox="0 0 24 24" fill="currentColor" class="hidden dark:block w-4 h-4" aria-hidden="true">[... 623 characters folded ...]
</svg> </summary> <fieldset id="header-theme-button-choices" class="absolute right-0 top-full z-50 mt-2 min-w-44 rounded-xl border border-primary-surface bg-surface p-1 shadow-lg"> <legend class="sr-only">Theme</legend> <label class="flex min-h-11 cursor-pointer items-center justify-between gap-4 rounded-lg px-3 text-sm text-default hover:bg-primary-soft-alpha has-focus-visible:outline has-focus-visible:outline-2 has-focus-visible:outline-primary-surface"> Light <input type="radio" name="header-theme-button-preference" value="light" data-theme-preference class="h-4 w-4 appearance-auto accent-current"> </label><label class="flex min-h-11 cursor-pointer items-center justify-between gap-4 rounded-lg px-3 text-sm text-default hover:bg-primary-soft-alpha has-focus-visible:outline has-focus-visible:outline-2 has-focus-visible:outline-primary-surface"> Dark <input type="radio" name="header-theme-button-preference" value="dark" data-theme-preference class="h-4 w-4 appearance-auto accent-current"> </label><label class="flex min-h-11 cursor-pointer items-center justify-between gap-4 rounded-lg px-3 text-sm text-default hover:bg-primary-soft-alpha has-focus-visible:outline has-focus-visible:outline-2 has-focus-visible:outline-primary-surface"> System <input type="radio" name="header-theme-button-preference" value="system" data-theme-preference class="h-4 w-4 appearance-auto accent-current"> </label> </fieldset> </details> <button type="button" data-header-search-button aria-label="Search the docs" aria-controls="header-search-overlay" aria-expanded="false" class="order-5 inline-flex h-11 w-11 items-center justify-center rounded-full text- [... 102 characters folded ...]>
<svg width="1em" height="1em" viewBox="0 0 24 24" fill="currentColor" class="w-4 h-4 text-secondary hover:text-default transition-colors">[... 578 characters folded ...]
</svg> </button> <!-- Mobile Menu Button --> <button id="header-drawer-button" type="button" aria-label="Toggle menu" aria-controls="drawer" aria-expanded="false" class="order-6 relative right-1 inline-flex h-11 w-11 items-center justify-center rounded-full text-se [... 95 characters folded ...]>
<svg width="1em" height="1em" viewBox="0 0 24 24" fill="currentColor" class="w-4 h-4 text-secondary hover:text-default transition-colors">[... 122 characters folded ...]
</svg> </button>
</div> <!-- Links -->
<nav class="order-3 hidden min-w-0 items-center justify-center gap-1 lg:col-start-2 lg:row-start-1 lg:flex">
<div class="group relative shrink-0"> <a href="/" class="flex items-center gap-1 text-sm py-1 px-2.5 rounded-md text-default bg-primary-soft"> Home </a>
</div>
<div class="group relative shrink-0" data-site-visibility-exclude="chatgpt-docs"> <a href="/api/docs" class="flex items-center gap-1 text-sm py-1 px-2.5 rounded-md text-primary-soft hover:text-default hover:bg-primary-soft-alpha" aria-haspopup="menu"> API
<svg width="1em" height="1em" viewBox="0 0 24 24" fill="currentColor" class="h-3.5 w-3.5 shrink-0" aria-hidden="true">[... 179 characters folded ...]
</svg> </a>
<div class="invisible opacity-0 absolute left-0 top-full z-50 mt-2 min-w-full w-max transition-opacity duration-150 group-hover:visible group-hover:opacity-100 group-has-focus-visible:visible group-has-focus-visible:opac [... 111 characters folded ...]>
<div class="overflow-hidden rounded-md border border-primary-surface bg-surface shadow-md ring-1 ring-black/5 dark:ring-white/10">
<div> <a role="menuitem" href="/api/docs" class="block px-4 py-3 text-sm text-default transition-colors hover:bg-primary-soft-alpha dark:hover:bg-alpha-10 hover:text-default">
<div class="flex flex-col gap-1">
<div class="flex items-center gap-1.5 font-medium"> Overview
</div>
<div class="text-sm text-secondary"> Get started with the OpenAI API
</div>
</div> </a><a role="menuitem" href="/api/docs/models" class="block px-4 py-3 text-sm text-default transition-colors hover:bg-primary-soft-alpha dark:hover:bg-alpha-10 hover:text-default">
<div class="flex flex-col gap-1">
<div class="flex items-center gap-1.5 font-medium"> Models
</div>
<div class="text-sm text-secondary"> Explore models and compare capabilities
</div>
</div> </a><a role="menuitem" href="/api/docs/guides/agents" class="block px-4 py-3 text-sm text-default transition-colors hover:bg-primary-soft-alpha dark:hover:bg-alpha-10 hover:text-default">
<div class="flex flex-col gap-1">
<div class="flex items-center gap-1.5 font-medium"> Agents
</div>
<div class="text-sm text-secondary"> Build persistent agents on hosted infrastructure
</div>
</div> </a><a role="menuitem" href="/api/docs/guides/tools" class="block px-4 py-3 text-sm text-default transition-colors hover:bg-primary-soft-alpha dark:hover:bg-alpha-10 hover:text-default">
<div class="flex flex-col gap-1">
<div class="flex items-center gap-1.5 font-medium"> Tools
</div>
<div class="text-sm text-secondary"> Connect models to tools and data
</div>
</div> </a><a role="menuitem" href="/api/docs/guides/audio" class="block px-4 py-3 text-sm text-default transition-colors hover:bg-primary-soft-alpha dark:hover:bg-alpha-10 hover:text-default">
<div class="flex flex-col gap-1">
<div class="flex items-center gap-1.5 font-medium"> Audio & voice
</div>
<div class="text-sm text-secondary"> Build speech and realtime voice experiences
</div>
</div> </a><a role="menuitem" href="/api/docs/guides/production-best-practices" class="block px-4 py-3 text-sm text-default transition-colors hover:bg-primary-soft-alpha dark:hover:bg-alpha-10 hover:text-default">
<div class="flex flex-col gap-1">
<div class="flex items-center gap-1.5 font-medium"> Production
</div>
<div class="text-sm text-secondary"> Deploy and scale your API integrations
</div>
</div> </a><a role="menuitem" href="/api/reference/overview" class="block px-4 py-3 text-sm text-default transition-colors hover:bg-primary-soft-alpha dark:hover:bg-alpha-10 hover:text-default">
<div class="flex flex-col gap-1">
<div class="flex items-center gap-1.5 font-medium"> API reference
</div>
<div class="text-sm text-secondary"> Explore endpoints, parameters, and responses
</div>
</div> </a>
</div>
</div>
</div>
</div>
<div class="group relative shrink-0" data-site-visibility-exclude="chatgpt-docs"> <a href="/chatgpt" class="flex items-center gap-1 text-sm py-1 px-2.5 rounded-md text-primary-soft hover:text-default hover:bg-primary-soft-alpha" aria-haspopup="menu"> ChatGPT
<svg width="1em" height="1em" viewBox="0 0 24 24" fill="currentColor" class="h-3.5 w-3.5 shrink-0" aria-hidden="true">[... 179 characters folded ...]
</svg> </a>
<div class="invisible opacity-0 absolute left-0 top-full z-50 mt-2 min-w-full w-max transition-opacity duration-150 group-hover:visible group-hover:opacity-100 group-has-focus-visible:visible group-has-focus-visible:opac [... 111 characters folded ...]>
<div class="overflow-hidden rounded-md border border-primary-surface bg-surface shadow-md ring-1 ring-black/5 dark:ring-white/10">
<div> <a role="menuitem" href="/plugins" class="block px-4 py-3 text-sm text-default transition-colors hover:bg-primary-soft-alpha dark:hover:bg-alpha-10 hover:text-default">
<div class="flex flex-col gap-1">
<div class="flex items-center gap-1.5 font-medium"> Plugins
</div>
<div class="text-sm text-secondary"> Extend ChatGPT and Codex
</div>
</div> </a><a role="menuitem" href="/siwc" class="block px-4 py-3 text-sm text-default transition-colors hover:bg-primary-soft-alpha dark:hover:bg-alpha-10 hover:text-default">
<div class="flex flex-col gap-1">
<div class="flex items-center gap-1.5 font-medium"> Sign in with ChatGPT
</div>
<div class="text-sm text-secondary"> Apps powered by your user's ChatGPT plan
</div>
</div> </a><a role="menuitem" href="/commerce" class="block px-4 py-3 text-sm text-default transition-colors hover:bg-primary-soft-alpha dark:hover:bg-alpha-10 hover:text-default">
<div class="flex flex-col gap-1">
<div class="flex items-center gap-1.5 font-medium"> Commerce
</div>
<div class="text-sm text-secondary"> Build commerce flows in ChatGPT
</div>
</div> </a><a role="menuitem" href="/ads" class="block px-4 py-3 text-sm text-default transition-colors hover:bg-primary-soft-alpha dark:hover:bg-alpha-10 hover:text-default">
<div class="flex flex-col gap-1">
<div class="flex items-center gap-1.5 font-medium"> Ads
Shown with 175 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 358 KB.
Reading view the text a plain-fetch client can extract
title: OpenAI Developers
OpenAI for developers
For the complete documentation index, see llms.txt . Markdown versions of documentation pages are available by appending .md to the page URL. ChatGPT Start searching API Dashboard Try ChatGPT Theme Light Dark System Home API Overview Get started with the OpenAI API Models Explore models and compare capabilities Agents Build persistent agents on hosted infrastructure Tools Connect models to tools and data Audio & voice Build speech and realtime voice experiences Production Deploy and scale your API integrations API reference Explore endpoints, parameters, and responses ChatGPT Plugins Extend ChatGPT and Codex Sign in with ChatGPT Apps powered by your user's ChatGPT plan Commerce Build commerce flows in ChatGPT Ads Publish and measure ads in ChatGPT Workspace Agents Trigger published ChatGPT workspace agents ChatGPT + Codex user docs Guides and product docs for ChatGPT and Codex Use cases Example workflows and tasks teams can take on with ChatGPT or Codex Docs Use cases Training Resources Resources Showcase Demo apps to get inspired Blog Learnings and experiences from developers Cookbook Notebook examples for building with OpenAI models Learn Docs, videos, and demo apps for building with OpenAI Community Programs, meetups, and support for builders Search the docs Search docs Suggested responses create
1782 more words follow in the initial HTML.
| Check | Result | Detail |
|---|---|---|
| H1 in the initial HTML | Found one H1 | First H1: OpenAI for developers |
| First 200 words in the initial HTML | Found 200 of 200 words | The initial HTML carries 1982 words of visible text; the first 200 are marked in the left pane. |
| llms.txt present and linked | Found present and linked | 6201 bytes, 40 links. Structure grade A (6 of 6). The home page links it, which is how agents reached it in Ora's lab. |
| Markdown on request | Missing 200 text/html | Accept: text/markdown returned 200 with text/html; charset=utf-8. The server ignores the header. |
| Status of a made-up path | Found 404 | /agent-ready-html-missing-path-check returned 404: a real status code for a missing page. |
| JSON-LD types | Found WebSite | 1 schema.org type in JSON-LD blocks on the home page: WebSite. |
| OpenAPI link | Note none on the home page | No 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 developers.openai.com.
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
- Ora: AgentReady launch post (Ora's lab findings) https://ora.ai/blog/agentready-launch, read 4 November 2026
- Ora check catalogue, contract 1.38.0 (132 checks, 42 in the Access layer) https://ora.ai/api/checks, read 5 November 2026
- Ora home page (the fixing product is behind a waitlist) https://ora.ai/, read 5 November 2026
- Ora: Introducing Deep Scan (repeat scans) https://ora.ai/blog/introducing-deep-scan, read 5 November 2026
- Ora llms.txt (public URLs only) https://ora.ai/llms.txt, read 5 November 2026
- Vercel: Make your site readable by AI agents https://vercel.com/kb/guide/make-your-site-readable-by-ai-agents, read 4 November 2026
- llms.txt proposal (llmstxt.org) https://llmstxt.org/, read 4 November 2026
Last reviewed 5 November 2026