# ChatCrawler

> ChatCrawler is a search engine for public Telegram. It discovers public groups and channels, crawls their open feeds through the official Telegram API and makes them findable — the way a web search engine does for websites. Every venue (group or channel) has a public archive; every post has its own permanent URL.

Archive pages are server-rendered HTML: no JavaScript is needed to read any of them. All times are UTC.

## How the archive is organised

- Venue card: `https://chatcrawler.link/v/{username or id}` — title, description, members, username history, archive by month.
- Latest posts: `https://chatcrawler.link/v/{ref}/m` — the newest 25 posts; older ones via `?p=1`, `?p=2`, …
- Month: `https://chatcrawler.link/v/{ref}/m?ym=YYYY-MM` — calendar of the month with the number of posts per day.
- Day: `https://chatcrawler.link/v/{ref}/m?d=YYYY-MM-DD` — every post of that day, 100 per page (`&p=1`, `&p=2`, … on busy days).
- Post: `https://chatcrawler.link/v/{ref}/m/{message_id}` — one post with its date, author and reply context; links to its day.

Any day of any venue is three links away from the venue card: card → month → day.

## Catalog and statistics

- Catalog hub: `https://chatcrawler.link/c` — rankings, topics, languages. Channels only: `https://chatcrawler.link/c/channels`; groups only: `https://chatcrawler.link/c/groups`.
- Topic: `https://chatcrawler.link/c/{topic}`, by venue type: `https://chatcrawler.link/c/{topic}/groups`, `https://chatcrawler.link/c/{topic}/channels`.
- Language: `https://chatcrawler.link/c/lang/{code}`; language × topic: `https://chatcrawler.link/c/lang/{code}/{topic}` (optionally `/groups` or `/channels`).
- Rankings: `https://chatcrawler.link/c/top/{metric}` — score, members, growth, active, views, er, cited, authors, new.
- Venue statistics: `https://chatcrawler.link/v/{ref}/stats` — subscribers history, activity, reach and ER, posting hours, top posts, who cites the venue.
- Methodology — every formula and threshold behind the numbers: `https://chatcrawler.link/methodology`.
- Venue pages open with a one-line verdict computed from those numbers; "no data" means we could not count, zero means we counted and found nothing. Posts that a channel publishes as itself are not part of the index, so reach and ER exist only where the channel's posts are indexed.

## Venue search

- `https://chatcrawler.link/c/search?q=...` — find public channels and groups by title, @username or a word from the description, with filters: `kind=channel|group`, `lang={language}`, `topic={topic}`, `size=s|m|l|xl` (audience size), `act=active`, `fresh=7d|30d` (last message), `sort=rel|members|growth|act|fresh`, `page=N`. Search result pages are not meant to be indexed.

## Discovery

- [Sitemap index](https://chatcrawler.link/sitemap.xml): venue cards, feeds, statistics, month archives and catalog pages
- [Catalog of venues by topic](https://chatcrawler.link/c)
- [How the numbers are counted](https://chatcrawler.link/methodology)
- [Venue search](https://chatcrawler.link/c/search)
- [About ChatCrawler](https://chatcrawler.link/about)
- [FAQ](https://chatcrawler.link/faq)
- [Limits of the index](https://chatcrawler.link/limits)
- [Removal requests](https://chatcrawler.link/removal)

## Citing

Link to a post (`/v/{ref}/m/{message_id}`) or to a day (`/v/{ref}/m?d=YYYY-MM-DD`). When a venue has a public @username, every post page also links to the original post in Telegram.