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FormSubmit

Protection

Spam protection

How FormSubmit filters spam with honeypots, timing checks, heuristics, rate limiting and duplicate detection.

Spam protection is on for every form and every plan. Submissions pass through several layers; anything that looks like spam is stored in the form's Spam folder and doesn't count toward your monthly quota or trigger emails and integrations.

Layers

Honeypot

A hidden field (default name _gotcha) that people never see but naive bots fill in. Any value → the submission is discarded silently.

html
<input type="text" name="_gotcha" style="display:none" tabindex="-1" autocomplete="off">

You can rename the honeypot field in form settings if a bot learns the default name.

Time-to-submit

If your form sends _ts (the timestamp when the page rendered), submissions arriving faster than your threshold (default 2 seconds) are scored as likely spam. All JavaScript snippets from the form generator include it.

Content heuristics

We score link density, HTML/BBCode links, well-known spam phrases, URLs in name fields, mostly-uppercase text, empty submissions and long runs of foreign script combined with links.

Your blocked keywords

Add words or phrases in settings; any match marks the submission as spam.

Duplicates and rate limiting

Identical submissions to the same form within 10 minutes are flagged. Each IP can submit up to 20 times per minute per form; each form accepts up to 600 per minute.

Sensitivity

Each form has a sensitivity setting that controls how high the combined score must be:

SensitivityThresholdUse when
Low0.9You rarely get spam and false positives would be costly
Medium (default)0.7Most sites
High0.5Your form is heavily targeted

Need more?

  • Add a captcha — reCAPTCHA, hCaptcha or Turnstile with your own keys.
  • Restrict submissions to your site with the domain allowlist.

Read the full playbook in how to stop form spam.

Frequently asked questions

Why did a real submission end up in spam?

Usually because it contained many links or matched a blocked keyword. Open it in the Spam folder and mark it as not spam, and consider lowering the sensitivity.

Do honeypot hits show up in my Spam folder?

No. Honeypot submissions are discarded immediately and the bot receives a normal success response, so it doesn't adapt.