An llms-txt.io alternative: what each tool is actually for
Comparison
Both validate an llms.txt. They are built around different jobs: llms-txt.io keeps files current for you as a managed service, this one is a free, account-free checker that fetches every link. Here is the honest split, so you can stop comparing and pick.
Competitor facts below were taken from llms-txt.io's own site on 8 October 2026 and are quoted where it matters. Pricing and features change — re-check before you rely on them.
The short version
If you need your llms.txt and llms-full.txt regenerated and kept up to date automatically, llms-txt.io sells exactly that and this tool does not do it at all. If you want to check a file you already control — thoroughly, with no signup — that is what this tool is built for.
At a glance
| llms.txt Validator (this site) | llms-txt.io | |
|---|---|---|
| Validating in the browser | Free | Free |
| Account to validate | None | None for the web validator |
| Link checking | Fetches every linked URL | “Samples your links and flags dead ones” |
| API | Free, no key, no quota | API key required; free tier 2,000 validations/mo |
| Keeps your file current | No | Managed sites, from $15/mo |
| Generates llms-full.txt | No | Yes, page budget by tier (20/50/100) |
| Spec v2 subpath files | Yes — /docs/llms.txt, walking up only on a real 404 | Not described on their validator page |
| Callable by an AI agent | MCP server + A2A agent card | Not described on their validator page |
| Paid plans | None | $15/mo Starter, $49/mo Pro |
The difference that actually changes a result: sampled vs every link
The most common real failure in an llms.txt is not bad Markdown. It is a file that parses perfectly and points at pages that have moved or died. Syntax-only linters never catch it.
llms-txt.io describes its check as “Samples your links and flags dead ones.” Sampling finds the problem when a lot of links are broken. It is the wrong instrument when one link out of sixty is dead — which is the normal case after a site reorganises, and the case an agent will hit.
This validator fetches every URL in the file, every run, and reports status per link. On a large file that is slower. That is the trade: completeness over speed.
Where llms-txt.io is the better buy
Three things it does that this tool genuinely does not:
- Managed sites. It regenerates your files on a schedule (weekly or daily), serves them from a stable URL, and fires a change webhook. If your content moves constantly and nobody owns the file, paying $15/mo to stop thinking about it is a reasonable trade.
- Generating
llms-full.txt. It builds the companion file for you, up to 20/50/100 pages by tier. This tool reports whether yours exists; it will not write it. - A commercial plan behind it. Paid tiers, email support, quota you can raise. For a team that needs someone to answer, that matters more than a feature checkbox.
If any of those is your actual problem, use theirs. This page is not trying to talk you out of it.
Where this one is the better fit
- You want depth on a file you already own. Every link fetched, structure checked against the spec, 0-100 split into Structure / Links / Best practices, and a specific fix per finding.
- You want it in CI without an account.
GET /api/validate?url=— no key, no quota, no signup. Nothing to provision and nothing to rotate. - Your file lives on a subpath. Spec v2 says a file covers the URLs under its path. Paste
example.com/docsand this targets/docs/llms.txt, walking up to the root only on a definitive 404 — a 403 or 5xx is treated as "unknown", not "absent". - You want the rest of the agent-readiness picture. The same run reports
robots.txt,sitemap.xml,ai.txt,llms-full.txt,llms.json, JSON-LD, canonical, hreflang, Markdown content negotiation, the spec-v2describedbyrelation, an A2A agent card and an MCP server card. - You want your agent to run the check. There is a real MCP server at
/mcpand an A2A agent card, so Claude, Cursor or your own agent can validate a domain as a tool call.
Honest limitations of this tool
So you do not find these out later:
- It does not generate or host
llms-full.txt, and it will not keep any file current for you. - There is no account, which also means no saved history, no team workspace and no support contract. You get a shareable permalink per report and that is the extent of persistence.
- Fetching every link makes a big file slower to check than a sampled one.
Can you use both?
Yes, and for some teams that is the right answer: let llms-txt.io generate and maintain the file, then run this validator over the result — in CI or as an agent tool — to confirm every link in the generated file still resolves. The two checks do not overlap much.