Verification Types
Button Click
Simple one-tap verification for low friction.
Math Challenge
Solve simple math problems.
Emoji Selection
Select the correct emoji from options.
Custom Question
Create your own verification questions.
How It Works
User Joins
New member attempts to join the group.
Challenge Sent
CAPTCHA challenge is displayed to the user.
Verification
User completes the challenge.
Access Granted
Verified users gain full access.
Customization Options
Why CAPTCHA?
- First Line of Defense - Stop bots before they can even post.
- Reduce Workload - Less spam means less moderation.
- Community Quality - Better signal-to-noise ratio.
- Works with AI - Layered protection for maximum security.
Try the button captcha
One tap for a person, a wall for a bot script. This is the lightest of the verification types — and often all a group needs.
This is the exact button-press check a newcomer sees — try it.
How verification gates new members
When someone joins, Telm holds them at the entrance and sends a challenge — a single button tap, a small maths problem, an emoji to pick, or your own custom question. The account cannot participate until it passes, and if it does not respond within the verification window it is removed automatically. If a CAS check is enabled to run first, obviously flagged accounts are dealt with before a challenge is ever shown, so genuine joiners see the lightest step that still filters out automated joins. Timeout, maximum attempts, difficulty and the action on failure are all yours to set.
The point of CAPTCHA is friction that a script will not bother with but a person clears in a second, which stops mass bot joins at the door and cuts the volume everything downstream has to handle. It is deliberately a first line, not the whole wall: a determined human spammer can tap a button just like anyone else, which is why the AI pipeline still reads what verified members actually post. Keep the challenge easy unless you are under active attack — every extra step you add to slow bots also costs your real members a moment, and you can whitelist trusted users or bypass admins entirely.
Frequently asked questions
Won't captcha annoy my real members?
New joiners solve one quick challenge once — a button tap or a simple task that takes a few seconds. Humans pass it without thinking; bots and mass-join scripts don't. Most communities see zero complaints and a dramatic drop in bot accounts.
What happens if someone fails the captcha?
They simply can't post until they pass. You control the timeout and what happens after it — keep them restricted, kick them, or let them retry. Failed accounts never get to spam your members.
Does captcha stop bot raids?
It's the first line of defense: a raid of freshly-registered bots hits the captcha wall and can't post. Combined with the anti-raid shield — which detects join surges and locks the group down automatically — raids fizzle out before they reach your members.
Can I customize the challenge?
Yes — choose the challenge type, the greeting text, the time limit, and the action on failure, per group. You can also exempt members who join via trusted invite links.
Where teams use this
Real community types where this feature does the heavy lifting.
Shield your gaming server from trolls, spam bots, and toxic behavior. Let your members focus on playing.
Protect your crypto group from scammers, fake airdrops, and phishing links — including scams hidden inside images.
Create a safe learning environment. Filter inappropriate content and keep discussions on-topic and productive.
Related Features
Explore more ways Telm can help your community