FormSubmit Alternative (2026): Attachments, Limits, Upgrades

Does FormSubmit support file attachments on a multipart form?

Yes. FormSubmit.co accepts file attachments when the form uses enctype="multipart/form-data" and a file input; several file inputs are allowed, but together the files must stay under 10 MB, and FormSubmit emails them without keeping them or exposing them through its API (FormSubmit documentation, checked October 2, 2026).

Older guides still quote a 5 MB limit: that was the documented cap until early 2026 (see FormSubmit's change history below). Without the multipart enctype, the browser sends only the file name, so no attachment arrives. For the full setup and the reasons attachments go missing (AJAX submits, the 10 MB total, uploads sent before you confirm the form), see our guide to FormSubmit file uploads and attachments.

<form action="https://formsubmit.co/[email protected]"
      method="POST"
      enctype="multipart/form-data">
  <input type="email" name="email" required>
  <input type="file"  name="attachment">
  <button type="submit">Send</button>
</form>

The splitforms version uses the same enctype and posts to https://splitforms.com/api/submit; paid plans store up to 5 files of 5 MB each per submission, with links in the email and dashboard.

<form action="https://splitforms.com/api/submit"
      method="POST"
      enctype="multipart/form-data">
  <input type="hidden" name="access_key" value="YOUR_ACCESS_KEY">
  <input type="email" name="email" required>
  <input type="file"  name="attachment">
  <button type="submit">Send</button>
</form>

Stored files count toward your plan's storage: 500 MB on Pro and 5 GB on Annual. See how file uploads work on splitforms, or start from our HTML file upload form guide for the markup and accept/size attributes.

FormSubmit parameters

FormSubmit is configured with hidden inputs whose names start with an underscore:

AJAX endpoint: https://formsubmit.co/ajax/[email protected]. After your first confirmation, FormSubmit gives you a random-string alias to use instead of your email address.

What are FormSubmit's limits?

FormSubmit does a lot for a free service with no signup. Its limits show up once a form starts carrying leads you can't afford to lose:

• No dashboard. Submissions arrive as emails. There's no inbox to search, filter or mark as handled, and no CSV export.
• A 30-day archive with capped API reads. FormSubmit keeps submissions for 30 days, and you can call its API to read them 5 times a day.
• Attachments aren't kept. Files are emailed and then gone; you can't fetch them later through the API.
• Autoresponses have conditions. _autoresponse doesn't run for AJAX submissions or when reCAPTCHA is turned off.
• No paid plan. There's nothing to upgrade to when you need longer history, exports or file storage.
• Use the alias, not your address. Until you swap in the random-string alias FormSubmit sends when you confirm your email, your address is visible in the form's action URL.

FormSubmit facts at a glance (verified October 2, 2026)

splitforms is a competitor; prices were checked on each vendor's public pricing page on September 27, 2026 to October 10, 2026 (date per row). Archive dates come from web.archive.org snapshots: a “Seen” change happened between the linked snapshot and the one before it.

Has FormSubmit changed its limits?

• February 21, 2026: The combined attachment limit per submission rose from 5 MB to 10 MB. First seen in the February 21, 2026 archived snapshot; the previous snapshot still showed the old terms.

How does splitforms compare with FormSubmit?

In short: FormSubmit covers delivery well. splitforms adds the part that comes after delivery, a place to keep, search and export what people send you.

How does spam protection compare?

FormSubmit's defenses work at the form: reCAPTCHA is on by default, _honey drops submissions where a hidden field is filled, and _blacklist rejects submissions containing phrases you list (FormSubmit suggests 20 at most). They help, but there's no spam folder to review, and anything that slips through lands in your inbox.

splitforms adds automatic spam scoring on the server, on every plan including Free. Each submission is checked with:

• Content rules: link-stuffed messages, known spam phrases, disposable or malformed email addresses, suspicious domains, repeated text and gibberish
• Honeypot field detection: an invisible botcheck field that bots fill in and people never see
• Rate limiting: per-IP throttling that stops submission floods

Flagged submissions go to a spam folder in the dashboard instead of your inbox. If something real gets caught, mark it "Not spam" and that sender is trusted from then on.

Why does a submissions dashboard matter?

A dashboard is the difference between "I think someone contacted me last Tuesday" and "here are this month's leads, sorted and searchable."

The splitforms dashboard gives you:

1. Submission history: No automatic expiry on any plan, searchable by name, email, content or date
2. Read / unread tracking: mark submissions as handled so nobody replies twice
3. A spam folder: review flagged submissions without them cluttering your inbox
4. CSV export (paid plans): download submissions for your CRM, spreadsheet or backup

FormSubmit gives you an inbox. splitforms gives you an inbox plus a record you can come back to.

How do I migrate from FormSubmit to splitforms?

Most forms take about three minutes. Change the action URL, add your access key, and rename FormSubmit's underscore fields:

<!-- BEFORE: FormSubmit -->
<form action="https://formsubmit.co/[email protected]" method="POST">
  <input type="hidden" name="_subject" value="New enquiry">
  <input type="hidden" name="_next"    value="https://yoursite.com/thanks">
  <input type="text"  name="name"    required>
  <input type="email" name="email"   required>
  <textarea           name="message" required></textarea>
  <button type="submit">Send</button>
</form>

<!-- AFTER: splitforms -->
<form action="https://splitforms.com/api/submit" method="POST">
  <input type="hidden" name="access_key" value="YOUR_ACCESS_KEY">
  <input type="hidden" name="subject"    value="New enquiry">
  <input type="hidden" name="redirect"   value="https://yoursite.com/thanks">
  <input type="text"  name="name"    required>
  <input type="email" name="email"   required>
  <textarea           name="message" required></textarea>
  <button type="submit">Send</button>
</form>

• _subject becomes subject, and _replyto becomes replyto.
• _next becomes a hidden redirect field, which works on every plan.
• _honey becomes botcheck.
• _captcha and _blacklist can go; spam is scored on the server.
• _cc, _webhook and _autoresponse move to the form's dashboard settings. Webhooks and autoresponders are on paid plans.
• Keep enctype="multipart/form-data" and your file inputs; stored uploads need a paid plan.

Your other field names stay the same, and the form keeps working on any static host with no JavaScript.

How much does FormSubmit cost compared with splitforms?

FormSubmit costs nothing, and for a low-stakes contact form that's hard to beat. The cost shows up elsewhere: no inbox to search, a 30-day archive and files you can't get back. splitforms' Free plan covers your first 500 submissions; when you need a monthly allowance, webhooks or file storage, Pro is $5/month.

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