10 best free and open-source AI visibility tools (2026)
Ten free plans and MIT-licensed tools for AI visibility, from Promptwatch Explore (10 ChatGPT prompts) to Lettertrace and Cloudflare AI Crawl Control, with each limit stated.
Free AI visibility tools come in a few kinds. Some are free tiers of paid trackers, capped at a handful of prompts. Some are open-source projects you run on your own API keys. Others are not trackers at all: they watch AI crawlers on your server or score how readable your site is. Each answers a different question.
We rank tools by how much work they take off your plate: monitoring, recommending or doing. For free tools we also asked whether the free tier tells you something useful or only teases the paid plan.
How we picked
Every tool here has a free plan or a free open-source license listed in our catalog. Limits come from each tool's catalog entry, built from vendor pages read on 20 October 2026, except GetCito and HubSpot AI Search Grader, which come from their existing catalog entries. Where a vendor does not publish a limit, we say so. Mentio's free plan (three analyses in total, ChatGPT only) missed the cut because it works more like a trial.
The list
1. Promptwatch
Promptwatch Explore is free: 10 prompts, ChatGPT only, 1 project, 1 seat. That is small. Still, ten well-chosen buyer prompts on ChatGPT is enough to see whether you are named and who is named instead, and because Explore is the same platform as the paid plans, upgrading does not mean switching tools.
The reason it ranks first is the upgrade path. Essential ($95 a month, 7-day trial) moves you to 50 prompts across all tracked engines, 6,000 responses, 200K visitor events and 5 AEO articles written by Content Agents. Professional ($245 a month) adds crawler logs (25M), 150 prompts and 15 articles. No other free tier on this list grows into crawler logs, conversions and published content in one workspace.
2. Hikoo
Hikoo is a French GEO platform that calls itself an action layer, and its free plan already does a little work. You get 10 questions with 50 AI answers a month on ChatGPT, 2 competitors, 100 pages audited, 1 content suggestion and MCP access, with daily updates. The page audit checks headings, structured data, answer clarity, internal links and crawler access. That is more than a score.
The limit that matters is coverage. Free is ChatGPT only, and Gemini needs the €69 Monitoring plan (per site, excl. VAT). Prepared page fixes and the outreach agent sit on the €499 Agent plan, so the free tier recommends rather than executes.
3. Cloudflare AI Crawl Control
Cloudflare AI Crawl Control is a feature of the Cloudflare dashboard, free on every plan, including Free. If your site runs behind Cloudflare, it shows which AI crawlers request your pages, grouped by operator, with request volume, status codes, most-requested paths and robots.txt violations. Then it lets you act: allow or block each crawler from the same screen, which writes a WAF rule.
On the Free plan, crawlers are identified by user agent only, and referral metrics need a paid plan (Pro from $20). It shows fetches, not prompts or citations.
4. Known Agents
Known Agents, formerly Dark Visitors, measures bots and AI agents at the server or CDN level. The free plan gives 1 project and 100K events a month with a hard cap. It covers which crawlers hit which pages, AI chat referrals from ChatGPT, Claude, Gemini and others, and estimated citation counts inferred from agent fetches. Integrations include WordPress, Cloudflare, Fastly, Akamai, AWS CloudFront, Google Cloud and Vercel, which is wider than Cloudflare's own tool.
The limit is the event count. Every API call counts, and Known Agents suggests budgeting about twice your human visits, so a busy site will outgrow the free tier quickly. It also never asks the AI engines anything.
5. Lettertrace
Lettertrace is MIT-licensed. You can use the hosted version at no charge or self-host it on Next.js and Supabase via Docker or Vercel. Either way you bring your own API keys for Anthropic, OpenAI, Google and Perplexity and pay the providers per run, with no markup. It generates prompt variations from topics, tracks visibility, share of voice, prominence and sentiment, records cited sources, and ships with a REST API, an MCP server and a CLI.
Answers come from provider APIs, not the apps people use, and its "Google AI Overviews" is a Gemini API call with a forced-search prompt, not the Overview on a Google results page. It is also young: the repository dates from July 2026.
6. FoundInAI
FoundInAI is a Shopify app. Its free plan gives an AI visibility scan with a score, robots.txt and sitemap diagnostics, canonical and redirect checks, and a basic llms.txt generator. The generator is the useful part, because the file gets written for you.
The free plan has no citation checks. Those start on Basic at $9 a month (5 a day on ChatGPT and Perplexity), with five engines from Starter at $19. The app launched on the App Store in August 2026 with no reviews as of 20 October 2026, and its homepage and listing disagree on pricing.
7. GetCito
GetCito offers an MIT-licensed self-hosted dashboard alongside a paid managed GEO service. The self-host version tracks ChatGPT and Google AI Overviews with a weekly refresh, for one domain, on your own API keys, with community support.
That is a narrow free tier. The rest of GetCito is a service with a human team, from $599 a month on Growth (50 prompts across four engines plus written articles).
8. Amplitude AI Visibility
Amplitude AI Visibility is a module inside Amplitude's product analytics platform, included on every plan, Free among them (2M events a month, no card). It reports a visibility score, share of voice, competitor rankings and cited sources, and suggests page-level fixes. Its real advantage is the rest of Amplitude: AI-referred visitors can be followed through funnels, conversions and Session Replay.
The limits are narrow coverage and missing numbers. Amplitude's FAQ says it tracks ChatGPT and Google AI Overview only and you cannot change the model. Prompt capacity and refresh cadence are not published, and the free plan has "limited capabilities".
9. Gemmetric
Gemmetric scores how well AI systems can understand a business rather than tracking a long prompt list. The free Snapshot is a public GEO baseline for one site, up to 10 pages at depth 2, two snapshots per 30 days. Findings link to evidence, and paid plans package them as Fix Packs your team implements.
The limit is that the free Snapshot covers readability only. The full AI Visibility Score, AI Perception and the beta Citation Presence check need paid plans from $79 or $249 a month, and its product pages do not name the engines it queries.
10. HubSpot AI Search Grader
HubSpot AI Search Grader gives a free, one-shot score of your brand across ChatGPT, Perplexity and Gemini, with sentiment and a share-of-voice estimate, and needs no account. It is also the thinnest tool here: no history and no custom prompts, and HubSpot's own disclaimer says results are not guaranteed. The paid follow-up, HubSpot AEO, is $50 a month.
Comparison table
| Tool | Best for | Free tier | Key capability |
|---|---|---|---|
| Promptwatch | Starting small on the platform you will grow into | Explore: 10 prompts, ChatGPT, 1 project | Upgrade path to crawler logs, conversions and Content Agents |
| Hikoo | French brands that want fixes, not just a score | 10 questions, ChatGPT, 100 pages audited | Page audit plus MCP on free |
| Cloudflare AI Crawl Control | Sites already on Cloudflare | Included on Cloudflare Free | Allow or block AI crawlers |
| Known Agents | Bot traffic on any major CDN | 1 project, 100K events | Server-side crawler and referral analytics |
| Lettertrace | Developers who want control | MIT, hosted or self-hosted | Bring-your-own-key tracking with MCP and CLI |
| FoundInAI | Small Shopify stores | Scan, diagnostics, basic llms.txt | Writes llms.txt for you |
| GetCito | Trying an open-source tracker | MIT self-host, weekly, 1 domain | ChatGPT and AI Overviews on your own keys |
| Amplitude AI Visibility | Teams already on Amplitude | Included on Amplitude Free | AI referrals inside product analytics |
| Gemmetric | A readability baseline | Snapshot: 10 pages, 2 per 30 days | Evidence-linked findings |
| HubSpot AI Search Grader | A one-off conversation starter | Free one-shot score | Instant score on three engines |
Who should pick which
If you want to know whether ChatGPT recommends you, start with Promptwatch Explore. It asks the engine directly, and the paid plans build on the same workspace.
If your worry is bots rather than answers, use Cloudflare AI Crawl Control if you are on Cloudflare and Known Agents if you are not. Neither will tell you what the engines say.
If you are a developer and want to own the pipeline, Lettertrace is the better of the two open-source options, with more engines, an MCP server and a CLI. GetCito's self-host is narrower.
Shopify stores can take FoundInAI's free llms.txt generator, Amplitude customers can switch on AI Visibility, and French teams wanting a free audit with recommendations should try Hikoo.
Where free stops
Every other free tool here does one slice. The trackers sample a few prompts, the crawler tools see fetches but not answers, and the graders give one score with no history. None connects a crawl to a citation to a conversion, and none writes and publishes content.
That join is the work Promptwatch is built for. Agent Analytics logs AI crawler visits with a crawl-to-citation path, citation analytics show which pages, Reddit threads and YouTube videos get cited, and visitor analytics ties AI-referred visits to conversions. When the data shows a gap, Content Agents write the page and publish it to WordPress, Webflow or Framer after review. Start on the free Explore plan, and upgrade to Essential or Professional when ten ChatGPT prompts stop being enough.
Start at promptwatch.com.