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File Uploads

Store, export, and share files collected with your Basin forms.

Accepting Files

Enabling forms powered by Basin to accept file uploads is really easy. You simply have to add enctype="multipart/form-data" and accept-charset="UTF-8" to your form tag and you're all set.

Notice

Basin accepts files up to 100MB each. Uploaded files count against your plan's total file-storage allowance.

Single input example

<form accept-charset="UTF-8" action="https://usebasin.com/f/1a2b3c4d5e6f" enctype="multipart/form-data" method="POST">
...
<input type="file" name="resume" ></input>
...
</form>

Multi-input example

<form accept-charset="UTF-8" action="https://usebasin.com/f/1a2b3c4d5e6f" enctype="multipart/form-data" method="POST">
...
<input type="file" name="resume" ></input>
<input type="file" name="cover-letter" ></input>
<input type="file" name="application" ></input>
...
</form>

Multi-attachment input example

Your file input must include name="attachments[]" multiple for this use case to work.

<form accept-charset="UTF-8" action="https://usebasin.com/f/1a2b3c4d5e6f" enctype="multipart/form-data" method="POST">
...
<input type="file" name="attachments[]" multiple></input>
...
</form>

Links to attachments in notification emails, SMS, webhooks and integrations open the file for anyone who has the link, without signing in, so treat them as confidential. To require signing in as someone with access to the form, choose Include Secure Links to Attachments under Form → Settings → Notifications → Notification (Email) → Attachment Settings (Pro plan and above).

Inline Attachment Preview

By default, attachment links force a file download. If you'd like image attachments to open directly in the browser instead, enable Inline Attachment Preview under Form → Settings → General.

When enabled, images of the following types are served inline:

  • JPEG / JPG
  • PNG
  • GIF
  • WebP

All other file types continue to be served as downloads regardless of this setting.

Virus-scanned files

Attachments flagged as infected are never served inline — they always redirect to a warning page, even when Inline Attachment Preview is enabled.

Virus Scanning for attachments

On every plan, Basin scans each uploaded file for viruses and malware using Amazon GuardDuty Malware Protection for S3. Files are scanned inside AWS, where they're stored, and aren't sent to any other service.

  • Notification emails and webhooks wait for the scan result, for up to five minutes.
  • Files flagged as malicious are left out of notification emails and webhooks. Opening one from Basin shows a warning page first.
  • Each attachment shows its scan status in your dashboard: Scanned, Scanning, Malware detected, or Not scanned.
  • Some file types can't be scanned. These are still delivered and marked Not scanned.