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Yuhe He
Yuhe He

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How to Monitor Public Telegram Channels for Free (No API Key, No Bot)

#telegram #osint #python #monitoring

You can monitor public Telegram channels for free. No API key, no bot, no server bill. The trick is that Telegram exposes a web preview at t.me/s/<channel> that returns the last ~20 posts as plain HTML. Poll it.

The 20-line loop

import requests, re, time
URL = "https://t.me/s/<channel>"
seen = set()
while True:
    html = requests.get(URL, timeout=15).text
    for msg_id in re.findall(r'data-post="[^"]*-(\d+)"', html):
        if msg_id not in seen:
            seen.add(msg_id)
            print("new post", msg_id)   # hand off to your parser
    time.sleep(300)  # 5 min cadence
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That's it. Post IDs are sequential per channel, so a new max ID means a new post. Everything else — subscriber counts (data-count), view counts, forward chains, media URLs — is right there in the HTML.

What free gets you

  • Last ~20 posts per fetch (a window, not a stream)
  • Subscriber count snapshots (turn it into a time series by polling hourly)
  • Forward/repost flags — a proxy for coordinated amplification
  • Zero login, zero rate-limit drama at sane cadences (5+ minutes between hits per channel)

What free does not get you

  • Full history backfill. The preview window is a window; use the ?before=<post-id> cursor trick to page backward while posts are in range, and accept a coverage ceiling for anything older.
  • Private channels. Public means public.
  • Guaranteed dedupe across your own restarts — persist seen to disk, not memory.

The one design decision that decides whether you get paged at 3am

Polling cadence. 60 seconds is for trading bots that monetize seconds. For monitoring, alerts, and research, 5 minutes per channel, jittered, with a daily full-window reconciliation pass, survives Telegram preview hiccups, network blips, and your own deploys. A cadence design that degrades gracefully (miss a poll, catch up on the window) is worth more than a fast one that breaks on the first 503.

I run this pattern across ~200 channels for market and OSINT signals. The collection-layer playbook — cursor pagination, repost-ring flags, wording-diff alerting, the raw-storage discipline that keeps re-parsing free — is the $5 bundle here: https://heyuhe.gumroad.com/l/poddr. A free sample brief (a real one, with the flags and timelines applied) is here, pay what you want, $0 is fine: https://heyuhe.gumroad.com/l/ruldgm.

If this saved you an afternoon of reading broken 2017 tutorials, that's the deal I'm trying to make.

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