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Captcha Verification for New Telegram Members

Require new members to prove they are human with a one-tap captcha on join. Stop bot accounts before they post, with a 5-minute window and automatic removal.

7 min read
In short

Captcha asks every newcomer to tap a single button to prove they are human. Until they tap it they cannot say a word, and any account that does not verify within 5 minutes is removed. It is one tap, so real people barely notice it while automated bots are stopped cold. Works on every plan.

Turn on CAPTCHA so new members tap a button to verify.

Want to set this up? Do it right in your Telm account.

Open in your dashboard

1How the captcha works

The moment someone joins, the bot posts a short welcome and an inline button that reads I am not a bot. Until they tap it, the newcomer is held back and cannot send messages, media or links.

One tap restores normal posting rights instantly. If they do not verify within 5 minutes, the bot removes them from the group. Removal is not a ban, so a real person who missed the window can simply rejoin and try again.

The button only responds to the exact person who joined. Another member cannot tap it on their behalf, so a bot cannot be waved through by an accomplice.

2Why a one-tap check works

Mass spam runs on automation. A script joins a group and posts immediately, then repeats across thousands of chats. A human check breaks that pipeline, because the script has no way to press the button and simply moves on instead of solving it.

Because it is a single tap and not a distorted-text puzzle, the friction for real people is close to zero. There is nothing to read, type or get wrong, which is why the captcha stops bots without driving away genuine newcomers.

3What the newcomer sees

The experience is deliberately simple. The newcomer gets a friendly greeting with their name, a line explaining they have 5 minutes to verify, and a single button labelled I am not a bot.

One tap clears the challenge and unlocks the chat. There is no separate app, no external link and no personal information requested, which keeps trust high and abandonment low.

4Captcha vs DM verification

Telm offers two on-join checks controlled by a single Verification mode setting: in-group captcha, the button described here, and DM verification, where the newcomer confirms in the bot's private chat.

Verification mode takes priority over the older standalone captcha toggle. Set it to captcha for the in-group button, dm for the private-chat flow, or off to disable both. The two never run at the same time, so pick the one that fits your group.

  • captcha: the check happens in the group with a visible button. Simplest option, works on every plan.
  • dm: the check moves to the bot's private chat, keeping the group feed clean. Requires Basic or higher.
  • off: no on-join human check; rely on restrictions and content moderation instead.

5When captcha is the right choice

In-group captcha is the default recommendation for most groups because it is universal and needs no upgrade.

  • Small to mid-size communities where a couple of verification messages in the feed are not a problem.
  • Groups on the Free plan, since in-group captcha is available everywhere while DM verification needs Basic or higher.
  • Chats where you want newcomers to see they were checked, which quietly signals the group is moderated.
  • As a fallback layer: even if a bot somehow verifies, content moderation still inspects everything it posts.

6Best practices

Captcha is strongest as one layer among several rather than your only defence.

  • Combine captcha with new member restrictions so even a verified newcomer cannot immediately drop links.
  • Keep the new-user guard on to inspect the first messages of anyone who passes.
  • For large or public groups, consider switching to DM verification so the feed stays clean.
  • Let the anti-raid shield force a captcha automatically during join floods, even if you normally keep it off.

7Common mistakes

A few misunderstandings lead people to under-use or misjudge the captcha.

  • Assuming removal is a ban. Accounts that miss the window are only removed and can rejoin, so a genuine person is never permanently locked out.
  • Turning verification off entirely because a message appears in the feed, when DM verification solves exactly that without losing protection.
  • Relying on captcha alone against a determined attacker, rather than layering it with restrictions and moderation.
  • Forgetting that Verification mode overrides the legacy captcha toggle, so setting mode to off disables the check even if the old toggle looks on.

8How to enable

Open the group in the dashboard, go to New members, and in the Verification card set the mode to captcha. Save, and the check applies to everyone who joins next.

You can combine captcha with new member restrictions for layered protection, and the protection presets can turn it on for you as part of a recommended setup.

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