Headless web analytics for the AI age

Extremely fast, capable, and affordable analytics in a 2 KB tag.

Capless skips the dashboard and just provides a low-level API; perfect for your AI agent.

pageviewclickscrollreplayerroryour visit so far, one bar per second

Install

Paste this before </head>. We made the key in your browser, so you don't need an account.

<script async src="https://c.capless.sh/c.js"
  data-key="…"></script>

Or tell your coding agent:

Add Capless analytics to this site. Run `curl -s https://analytics.capless.sh/new` and follow what it prints.

Events

Each event is one JSON record, with the session, device and location filled in. You don't define a schema, and nothing is sampled.

pageview
click
submit
error
pageleave
custom
identify

Size

Compressed size of each vendor's main analytics script
Google tag	153.1 KB
PostHog	105.1 KB
Mixpanel	32.8 KB
Capless	2.0 KB

The main script of each, compressed, as Chrome downloaded it on October 31, 2026. Replay is a separate 1.7 KB file that only loads for sessions being recorded.

Privacy

There are no cookies, just an anonymous ID in localStorage.
We never store IP addresses.
What people type is masked in the browser, before it's sent. Try it: Type something → ***************
You can erase a user's data with one predicate, like entry.userId == "u_123".

Query

Reads take a CEL filter and map, which run next to the data. This console runs them on what your visit has stored so far. For totals and trends, the same events are in ClickHouse, where you can use SQL.

POST /v1/streams/$web.events/read, your visit only.

Run a query to see what Capless returns.

Agents

Your coding agent can install Capless and query it without help. It has an MCP server, a signup API, AGENTS.md and llms.txt to work from.

claude mcp add --transport http capless https://mcp.capless.sh/mcp

Price

Starter	$5 a month	one member
Team	$29 per member a month	unlimited members

Each project includes 250,000 events, 2,500 replays and 10 GB a month, on as many sites as you like. After that it's $2 per million events, $0.50 per 1,000 replays and $0.10 per GB-month. The first 14 days are free, and you don't need a card.

What the same volume costs elsewhere:

Monthly volume	Capless Starter (1 member)	PostHog	Mixpanel Growth	Amplitude Plus	LogRocket
10M events	$24.50	$324.40	$840 (annual billing), $1,176 (monthly billing)	$720	priced per session
100M events	$204.50	$2,618.40	contact sales	contact sales	priced per session
100k session replays	$53.75	$272.50	not published	not published	$717 (billed annually)
10M events + 100k replays	$73.25	$596.90	not published	not published	$717 (billed annually)

Sources and details

Claim

Enter your email to keep what your tag collects. You get the dashboard, replays, SQL, API keys and a team.