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: 7 of 7 checks found.
Initial HTML what a plain fetch receives
<!DOCTYPE html>
<html lang="en" class="__className_6443a8" data-scroll-behavior="smooth">
<head>
<meta charSet="utf-8"/>
<meta name="viewport" content="width=device-width, initial-scale=1"/>
[... 49 more head elements folded ...]
<title>Customer.io: Customer Engagement Platform For Better Outcomes
</title>
<meta name="description" content="Customer.io is a customer engagement platform for creating personalized journeys and better business outcomes across email, push, SMS, and in-app messaging."/>
[... 5 more head elements folded ...]
<meta name="generator" content="Next.js"/>
[... 3 more head elements folded ...]
<meta name="robots" content="index, follow"/>
[... 3 more head elements folded ...]
<link rel="canonical" href="https://customer.io"/>
[... 24 more head elements folded ...]
</head>
<body>
<div hidden=""><!--$--><!--/$-->
</div><!--$--><!--/$-->
<style>[... 1,203 characters folded ...]
</style>
<header class="sticky top-0 z-40 w-full" role="banner">
<div class="h-header text-ink ease-out-fast bg-surface inverse:bg-surface-stronger size-full border-b transition-all">
<div class="h-header mx-auto max-w-420 px-5 md:px-8">
<div class="flex size-full items-center justify-between xl:justify-baseline">
<div class="flex gap-x-10 pr-8 xl:flex-1 xl:pr-0"><span data-state="closed" data-slot="context-menu-trigger" class="select-none" style="-webkit-touch-callout:none"><a aria-label="Customer.io home" title="Customer.io home" class="text-spruce-700 inverse:text-ink relative flex items-center gap-1.25 [&>svg]:w-38" href="/">
<svg width="150" height="auto" viewBox="0 0 200 27" fill="none" xmlns="http://www.w3.org/2000/svg">[... 6,232 characters folded ...]
</svg></a></span>
</div>
<div class="hidden lg:block">
<nav aria-label="Main" data-orientation="horizontal" dir="ltr" class="z-40">
<div style="position:relative">
<ul data-orientation="horizontal" class="group flex flex-1 list-none items-center justify-center gap-0" dir="ltr">
<li><button id="radix-_R_94ivb_-trigger-Platform" data-state="closed" aria-expanded="false" aria-controls="radix-_R_94ivb_-content-Platform" class="group h-header relative box-border w-max pr-2 pl-4 text-base font-semibold t [... 417 characters folded ...]>
<div class="flex items-center justify-center">Platform
<svg width="15" height="15" viewBox="0 0 15 15" fill="none" xmlns="http://www.w3.org/2000/svg" class="relative ml-1 size-4 transition-all duration-0 group-data-[state=open]:rotate-180" aria-hidden="true">[... 392 characters folded ...]
</svg>
</div></button>
</li>
<li><button id="radix-_R_94ivb_-trigger-Solutions" data-state="closed" aria-expanded="false" aria-controls="radix-_R_94ivb_-content-Solutions" class="group h-header relative box-border w-max pr-2 pl-4 text-base font-semibold [... 419 characters folded ...]>
<div class="flex items-center justify-center">Solutions
<svg width="15" height="15" viewBox="0 0 15 15" fill="none" xmlns="http://www.w3.org/2000/svg" class="relative ml-1 size-4 transition-all duration-0 group-data-[state=open]:rotate-180" aria-hidden="true">[... 392 characters folded ...]
</svg>
</div></button>
</li>
<li><button id="radix-_R_94ivb_-trigger-Resources" data-state="closed" aria-expanded="false" aria-controls="radix-_R_94ivb_-content-Resources" class="group h-header relative box-border w-max pr-2 pl-4 text-base font-semibold [... 419 characters folded ...]>
<div class="flex items-center justify-center">Resources
<svg width="15" height="15" viewBox="0 0 15 15" fill="none" xmlns="http://www.w3.org/2000/svg" class="relative ml-1 size-4 transition-all duration-0 group-data-[state=open]:rotate-180" aria-hidden="true">[... 392 characters folded ...]
</svg>
</div></button>
</li>
<li class="relative"><a class="group h-header relative box-border w-max pl-4 text-base font-semibold tracking-normal transition-all delay-0 duration-0 focus:bg-transparent focus:outline-hidden disabled:pointer-events-none disabled:opacity-50 pr-4" data-radix-collection-item="" href="/pricing">Pricing</a>
</li>
</ul>
</div>
<div class="absolute top-full left-0 flex w-full justify-center">
</div>
</nav>
</div>
<div class="flex flex-1 items-center justify-end gap-2"><a href="https://fly.customer.io/login" target="_blank" class="group ring-offset-background focus-visible:ring-ring relative z-1 inline-flex items-center justify-center gap-2 rounded-full font-semibold whitespace-nowrap [... 192 characters folded ...]>Sign in</a><a href="https://fly.customer.io/signup" target="_blank" class="group ring-offset-background focus-visible:ring-ring relative z-1 items-center justify-center gap-2 rounded-full font-semibold whitespace-nowrap transition- [... 265 characters folded ...]><span class="relative flex min-h-10 flex-col justify-center overflow-hidden"><span class="relative translate-y-0 transition-all ease-out group-hover:-translate-y-10 group-hover:opacity-0">Get started</span><span class="absolute translate-y-10 opacity-0 transition-all ease-out group-hover:translate-y-0 group-hover:opacity-100">Get started</span></span></a><a class="group ring-offset-background focus-visible:ring-ring relative z-1 items-center justify-center gap-2 rounded-full font-semibold whitespace-nowrap transition-all focus-visible:ring-2 focus-visible:ring-offset-2 f [... 295 characters folded ...]><span class="relative flex min-h-10 flex-col justify-center overflow-hidden"><span class="relative translate-y-0 transition-all ease-out group-hover:-translate-y-10 group-hover:opacity-0">Book a demo</span><span class="absolute translate-y-10 opacity-0 transition-all ease-out group-hover:translate-y-0 group-hover:opacity-100">Book a demo</span></span></a>
<div class="ml-2 inline-flex lg:hidden"><button type="button" aria-haspopup="dialog" aria-expanded="false" aria-controls="radix-_R_2d4ivb_" data-state="closed">
<svg data-sanity-icon="menu" width="1em" height="1em" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" class="size-7"><path d="M3 12H21M3 6H21M3 18H21" stroke="currentColor" stroke-width="1.5" stroke-linecap="square"></path>
</svg></button>
</div>
</div>
</div>
</div>
</div>
</header>
<main class="grow">
<script type="application/ld+json">[... 1,145 characters folded ...]
</script>
<section class="overflow-x-clip py-14 sm:py-16 md:py-20 lg:py-24 relative pt-8 lg:pt-20">
<div class="relative z-10 container">
<div class="flex flex-col gap-8">
<h1 class="text-heading-display -mb-2">More impact <br class="hidden md:block"/>from every <span class="inline-grid items-center align-baseline" aria-live="polite"><span class="pointer-events-none invisible overflow-visible whitespace-nowrap [grid-area:1/1]" aria-hidden="true">message</span><span class="inline-flex whitespace-nowrap [grid-area:1/1] text-brand"><span class="my-[-0.1em] inline-block overflow-hidden py-[0.1em]"><span class="inline-block" style="opacity:1;transform:none">m</span></span><span class="my-[-0.1em] inline-block overflow-hidden py-[0.1em]"><span class="inline-block" style="opacity:1;transform:none">e</span></span><span class="my-[-0.1em] inline-block overflow-hidden py-[0.1em]"><span class="inline-block" style="opacity:1;transform:none">s</span></span><span class="my-[-0.1em] inline-block overflow-hidden py-[0.1em]"><span class="inline-block" style="opacity:1;transform:none">s</span></span><span class="my-[-0.1em] inline-block overflow-hidden py-[0.1em]"><span class="inline-block" style="opacity:1;transform:none">a</span></span><span class="my-[-0.1em] inline-block overflow-hidden py-[0.1em]"><span class="inline-block" style="opacity:1;transform:none">g</span></span><span class="my-[-0.1em] inline-block overflow-hidden py-[0.1em]"><span class="inline-block" style="opacity:1;transform:none">e</span></span></span></span>
</h1>
<p class="max-w-[39ch] md:text-xl text-ink">Turn customer data into personalized experiences <br class="hidden md:block"/>that drive better business outcomes.
</p>
<div class="flex w-full flex-col items-center gap-4 sm:items-start">
<div class="flex w-full flex-col items-center justify-center gap-3 py-1 sm:flex-row sm:justify-start"><a href="https://fly.customer.io/signup" target="_blank" rel="noopener noreferrer" class="group ring-offset-background focus-visible:ring-ring relative z-1 inline-flex items-center justify-center gap-2 rounded-full font- [... 307 characters folded ...]><span class="relative flex min-h-10 flex-col justify-center overflow-hidden"><span class="relative translate-y-0 transition-all ease-out group-hover:-translate-y-10 group-hover:opacity-0">Get started</span><span class="absolute translate-y-10 opacity-0 transition-all ease-out group-hover:translate-y-0 group-hover:opacity-100">Get started</span></span></a><a class="group ring-offset-background focus-visible:ring-ring relative z-1 inline-flex items-center justify-center gap-2 rounded-full font-semibold whitespace-nowrap transition-all focus-visible:ring-2 focus-visible:rin [... 311 characters folded ...]><span class="relative flex min-h-10 flex-col justify-center overflow-hidden"><span class="relative translate-y-0 transition-all ease-out group-hover:-translate-y-10 group-hover:opacity-0">Book a demo</span><span class="absolute translate-y-10 opacity-0 transition-all ease-out group-hover:translate-y-0 group-hover:opacity-100">Book a demo</span></span></a>
</div>
<ul class="flex flex-col flex-nowrap gap-1 text-xs sm:flex-row sm:gap-2.5 text-subtle items-center">
<li class="flex items-center gap-1 text-nowrap"><span class="bg-verdant-25 inverse:bg-spruce-700 rounded-full p-0.5">
<svg data-sanity-icon="check-circle-broken" width="1em" height="1em" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">[... 502 characters folded ...]
</svg></span>14-day free trial
</li>
<li class="flex items-center gap-1 text-nowrap"><span class="bg-verdant-25 inverse:bg-spruce-700 rounded-full p-0.5">
<svg data-sanity-icon="check-circle-broken" width="1em" height="1em" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">[... 502 characters folded ...]
</svg></span>No credit card required
</li>
<li class="flex items-center gap-1 text-nowrap"><span class="bg-verdant-25 inverse:bg-spruce-700 rounded-full p-0.5">
<svg data-sanity-icon="check-circle-broken" width="1em" height="1em" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">[... 502 characters folded ...]
</svg></span>Cancel anytime
</li>
</ul>
</div>
</div>
</div>
</section>
<section class="relative overflow-x-clip py-16 sm:py-20 md:py-24 lg:py-32 bg-surface flex-col border-t hidden pt-0! pb-0! gap-12 sm:gap-16 md:gap-24">
<div class="container">
<div class="flex flex-col items-center border-x">
<div class="bg-surface-subtle flex w-full flex-col justify-center border-b py-2 px-4 md:px-8 items-center">
<p class="whitespace-pre-line text-sm text-center">The customer engagement platform <strong class="">trusted by 11,000+ brands</strong>
</p>
</div>
<div class="bg-stroke grid w-full grid-cols-3 items-center justify-items-center gap-px lg:grid-cols-6">
<div class="bg-surface flex size-full items-center justify-center p-4 md:p-6"><img alt="Higgsfield logo" loading="lazy" width="107" height="21" decoding="async" data-nimg="1" class="max-h-6 max-w-20 md:max-h-7 md:max-w-24" style="color:transparent;transform:translate(0px, -0.6px)" src="https://cdn [... 92 characters folded ...]>
</div>
<div class="bg-surface flex size-full items-center justify-center p-4 md:p-6"><img alt="Lovable logo" loading="lazy" width="102" height="18" decoding="async" data-nimg="1" class="max-h-6 max-w-20 md:max-h-7 md:max-w-24" style="color:transparent;transform:translate(0px, -1.3px)" src="https://cdn.sa [... 89 characters folded ...]>
</div>
<div class="bg-surface flex size-full items-center justify-center p-4 md:p-6"><img alt="Cursor logo" loading="lazy" width="98" height="23" decoding="async" data-nimg="1" class="max-h-6 max-w-20 md:max-h-7 md:max-w-24" style="color:transparent" src="https://cdn.sanity.io/images/onirtmj2/production/16019fbc08ecc85c8c1fc66d66eeb1a16f3cd3ca-300x72.svg"/>
</div>
<div class="bg-surface flex size-full items-center justify-center p-4 md:p-6"><img alt="Notion logo" loading="lazy" width="88" height="27" decoding="async" data-nimg="1" class="max-h-6 max-w-20 md:max-h-7 md:max-w-24" style="color:transparent;transform:translate(0px, -0.7px)" src="https://cdn.sani [... 87 characters folded ...]>
</div>
<div class="bg-surface flex size-full items-center justify-center p-4 md:p-6"><img alt="Gamma logo" loading="lazy" width="98" height="17" decoding="async" data-nimg="1" class="max-h-6 max-w-20 md:max-h-7 md:max-w-24" style="color:transparent" src="https://cdn.sanity.io/images/onirtmj2/production/6ad8e8e7de9ad70e9b9ea04fafc634d9f9dd7389-316x55.svg"/>
</div>
<div class="bg-surface flex size-full items-center justify-center p-4 md:p-6"><img alt="openrouter logo" loading="lazy" width="116" height="19" decoding="async" data-nimg="1" class="max-h-6 max-w-20 md:max-h-7 md:max-w-24" style="color:transparent" src="https://cdn.sanity.io/images/onirtmj2/production/6f15df0eac9cc25d700b1dc6fd2d01a2933e5659-532x85.svg"/>
</div>
</div>
</div>
</div>
</section>
<section class="relative overflow-x-clip py-16 sm:py-20 md:py-24 lg:py-32 bg-surface-subtle flex flex-col border-t pt-0! pb-0! gap-0 sm:gap-0 md:gap-0">
<div>
<div class="container">
<div class="relative z-1 flex aspect-video items-end justify-center overflow-clip p-6 pb-0 sm:p-8 sm:pb-0 md:p-16 md:pb-0 lg:p-20 lg:pb-0"><img alt="Modern office" loading="eager" decoding="async" data-nimg="fill" class="absolute z-0 aspect-video object-cover" style="position:absolute;height:100%;width:100%;left:0;top:0;right:0;bottom:0;color:transparent;ba [... 3529 characters folded ...]>
<div class="" style="opacity:0;transform:translateY(16px)"><img alt="Customer.io dashboard screen" loading="eager" width="2160" height="1215" decoding="async" data-nimg="1" class="relative z-1 aspect-video origin-top-left scale-150 overflow-clip rounded-t-xs md:scale-100 md:roun [... 3648 characters folded ...]>
</div>
</div>
</div>
</div>
</section>
<section class="relative overflow-x-clip py-16 sm:py-20 md:py-24 lg:py-32 bg-surface flex flex-col border-t border-b pt-0! pb-0! gap-12 sm:gap-16 md:gap-24">
<div class="container">
<div class="flex flex-col items-center overflow-clip border-x">
<div class="flex-1">
<style>[... 1,393 characters folded ...]
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 479 KB.
Reading view the text a plain-fetch client can extract
title: Customer.io: Customer Engagement Platform For Better Outcomes
More impact from every message m e s s a g e
Platform Solutions Resources Pricing Sign in Get startedGet started Book a demoBook a demo More impact from every messagemessage Turn customer data into personalized experiences that drive better business outcomes. Get startedGet started Book a demoBook a demo 14-day free trial No credit card required Cancel anytime The customer engagement platform trusted by 11,000+ brands case study case study case study case study The customer engagement platform trusted by 11,000+ brands case study case study case study case study case study case study case study case study Unify your data, messaging, and AI in one platform, so every customer interaction becomes a signal you can act on to lift conversion, retention, and revenue Intelligence that compounds Optimize each message with insights from every result. Small gains compound over time. Orchestration that scales One platform for every channel, message type, industry, and geography. Built for agents, not just humans Works with any AI tool using MCP, CLI, API or webhooks. Capabilities Everything you need to engage customers Platform overview Journeys Build automated campaigns that improve with every send. Audiences Reach the right people using data-driven segmentation. Data & integrations Use your customer data to drive better personalization. Design Studio Create beautiful
467 more words follow in the initial HTML.
| Check | Result | Detail |
|---|---|---|
| H1 in the initial HTML | Found one H1 | First H1: More impact from every message m e s s a g e |
| First 200 words in the initial HTML | Found 200 of 200 words | The initial HTML carries 667 words of visible text; the first 200 are marked in the left pane. |
| llms.txt present and linked | Found present and linked | 19429 bytes, 58 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 | Found text/markdown | Accept: text/markdown returned 200 with text/markdown; charset=utf-8. Vary: Accept is set. |
| 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 ContactPoint, ImageObject, Organization, Person and 2 more | 6 schema.org types in JSON-LD blocks on the home page: ContactPoint, ImageObject, Organization, Person, PostalAddress, WebSite. |
| OpenAPI link | Found linked | The home page links an OpenAPI file. 97 percent of openapi.json fetches in Ora's lab arrived through a link. |
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 customer.io.
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