The best free form builder with captcha is one that offers a captcha plus a second layer, such as email verification or filtering after the fact. Qwenvo has a Captcha block and AI triage that tags spam. Disclosure: we make Qwenvo, so it is listed first. No tool blocks all spam, and ours does not either.
Why one captcha is not enough
Spam on forms comes from bots and from real people. A captcha helps with bots. It does little against a person pasting a sales pitch into your contact form. A good defence has layers:
- A captcha, to slow automated posting.
- Email verification, so the address has to work.
- Friction controls, like password protection, closing after a date or a number of responses, and duplicate prevention.
- Filtering after submission, so the junk is tagged instead of reaching your inbox.
- Alerts that route real work, so the important messages stand out.
How we ranked
We looked at how many of those layers are free and in the form builder itself. For other tools, we have not verified captcha or filtering details, so we note what to check and link their pages.
At a glance
- Qwenvo: Captcha block, respondent email verification (one-time code), duplicate prevention, password protection, AI triage spam category with routing. $0.
- Tally: email verification is on its Business plan ($89 a month, $890 a year).
- Jotform: a long feature list; check its docs and pricing page for captcha options on the free plan.
- Fillout: check its docs for spam protection; free plan is capped at 1,000 responses a month.
- Google Forms: check its documentation for spam options; requiring a Google sign-in also puts off genuine customers.
1. Qwenvo
Best for: a public contact or lead form that needs defence in depth for no money.
- Captcha block: type
/and insert it in the form. - Respondent email verification: in the form's Settings, send a one-time code to the address they give.
- Prevent duplicate submissions and password protection for forms with a known audience.
- Close on a date or after N responses for sign-ups with a limit.
- AI triage: every submission gets a category, priority, sentiment and summary, and spam can be tagged so it does not look like a lead. Routing rules then send only the priorities or categories you choose to up to 5 email addresses or a Slack webhook.
Start with the contact form template and read how the spam filter works. Watch out for: triage is an AI classifier, so it can mislabel an unusual real message; look at the spam-tagged rows now and then.
2. Tally
Best for: simple forms with low spam risk. Watch out for: email verification and data retention sit on the Business plan, $89 a month or $890 a year.
3. Jotform
Best for: teams that want a long list of controls and a mobile app. Watch out for: the free plan has limits; check Jotform's pricing for what is included.
4. Fillout
Best for: forms that sync to Airtable or Notion, where you can filter in the database. Watch out for: the free plan stops at 1,000 responses a month, and a spam wave can use them up. See Fillout pricing.
5. Google Forms
Best for: internal forms where sign-in cuts bots. Watch out for: requiring a sign-in also blocks real customers, which is why it suits staff forms better than public ones.
A layered setup in 5 minutes
- Add the Captcha block with
/. - Turn on email verification if you need a reachable address.
- Turn on duplicate prevention if each person should answer once.
- Turn on AI triage and add a routing rule for urgent and high-priority submissions only.
- Review the lowest-priority rows weekly for false positives.
Where the others are better
If you already run a dedicated spam service on your site, an embed with that service in front may beat any built-in captcha. Qwenvo's embeds (Standard, Popup, Full page) work on any site that accepts HTML.
Questions people ask
Does Qwenvo have a captcha?
Yes, a Captcha block.
Will captcha stop all spam?
No. It slows bots; real people can still send junk. Combine it with verification and filtering.
Can AI triage tell me which submissions are spam?
It can tag them by category so you can filter them out. See AI form triage.
Every feature, $0, no card.
Protect your form free