Agent Readability Spec vs llms.txt
The map lists them as complementary: sites and agents commonly implement both.
| Agent Readability Spec ARS | llms.txt | |
|---|---|---|
| Lifecycle step | 4 Read: Give me the content | 4 Read: Give me the content |
| Answers | How readable is this site's content for AI agents, and what specifically should be fixed? | Where can an agent find a concise, curated map of a site's content, written for language models rather than browsers? |
| Governed by | Vercel; published in Vercel's own Knowledge Base with no external standards process | Jeremy Howard / Answer.AI; maintained as an open proposal in the AnswerDotAI/llms-txt GitHub repository with a public Discord for implementation discussion |
| Status (issuer's words) | A specification and scoring checklist, not a protocol; framed as best practices to implement voluntarily | "This is v2 of the proposal" — explicitly a community proposal open for input, not a standards-track document |
| Phase | draft | draft |
| Version | current (last updated 2026-03-23 per a secondary source; no version number or publication date is given on the page itself) (2026-03) | v2 (2026-08) |
| Form / transport | document format | well-known file |
| Found at | none | /llms.txt (or /<path>/llms.txt, e.g. /docs/llms.txt) |
| Adoption | unmeasured | claimed — Rankability (Tranco top-1000, June 2026: 8.7%) and SE Ranking (~300,000 domains analyzed: 10.13%) — independent third-party publisher-side counts, not our own probe |
| Evidence | 2 reported, 1 verified | 4 verified, 4 reported |
| Primary use case | Serve readable content to agents | Serve readable content to agents |
| Last verified | 2026-10-16 (current) | 2026-10-19 (current) |
| Specification | https://vercel.com/kb/guide/agent-readability-spec | https://llmstxt.org |
When to use which
- Choose Agent Readability Spec when your question is “How readable is this site's content for AI agents, and what specifically should be fixed?” and you accept its maturity: phase draft, adoption unmeasured.
- Choose llms.txt when your question is “Where can an agent find a concise, curated map of a site's content, written for language models rather than browsers?” and you accept its maturity: phase draft, adoption claimed (Rankability (Tranco top-1000, June 2026: 8.7%) and SE Ranking (~300,000 domains analyzed: 10.13%) — independent third-party publisher-side counts, not our own probe).
Read the full articles
- Agent Readability Spec: How readable is this site's content for AI agents, and what specifically should be fixed?
- llms.txt: Where can an agent find a concise, curated map of a site's content, written for language models rather than browsers?