If a large file still won't go through your form, it's almost always one of a handful of settings rather than a bug in the plugin. Big File Form Uploads relies on the Big File Uploads parent plugin for its limit and on a supported form plugin for the upload field — so the fix is usually making sure those pieces line up. Work through the checks below in order.
1. Confirm Both Plugins Are Active
Big File Form Uploads is an add-on. It needs the free Big File Uploads plugin installed and active to set your upload limit. Go to Plugins and verify that both of these are active:
- Big File Uploads (the free parent plugin)
- Big File Form Uploads (the add-on)
If Big File Uploads is missing or deactivated, your forms fall back to your host's default upload limits.
Two integrations also require the Pro version of the form plugin, because that's where the upload field lives:
- Fluent Forms — needs both Fluent Forms and Fluent Forms Pro active.
- Elementor — needs Elementor Pro active (the Form widget is a Pro feature).
2. Check Your Maximum Upload Size
Your limit is set in the parent plugin, not in the add-on:
- Go to Settings → Big File Uploads → Uploading Files.
- Confirm the Maximum upload file size is large enough for the files you're testing.
- Save your changes.
This single setting is what every supported form inherits.
3. Re-Save the Form
Gravity Forms and Forminator apply the chunked-upload settings to your fields when the form is saved. If you added an upload field before activating the add-on — or you're not sure — open the form and save it again:
- Gravity Forms — open the form and click Update.
- Forminator — open the form and click Save / Publish.
Contact Form 7, Fluent Forms, and Elementor upgrade their upload fields on the front end automatically, so no re-save is needed — just confirm the form actually contains an upload field:
- Contact Form 7 — a
[file]tag. - Fluent Forms — a File Upload (or Image Upload) field.
- Elementor — a field whose type is Upload in the Form widget.
4. Watch for a Per-Field Limit That's Lower
Your form plugin may have its own per-field maximum that overrides the global limit if it's set lower:
- Gravity Forms — check the File Upload field's Maximum File Size and Maximum Number of Files.
- Forminator — check the Upload field settings.
- Fluent Forms — check the field's Max File Size and Max File Count.
- Elementor — check the Upload field's Max. File Size and Max. Files (the effective limit is the smaller of this and your Big File Uploads max).
- Contact Form 7 — you don't need a
limit:option; the add-on sets it for you.
Raise any field-level limit that's smaller than your Big File Uploads setting.
5. Rule Out a Host Firewall or Security Rule
If small files upload fine but large ones fail partway through — or you see a 406, 403, or 413 error — your host's firewall or a security rule (such as ModSecurity) may be blocking the upload or admin-ajax.php requests. Big File Form Uploads can't bypass your host's firewall, and you wouldn't want it to.
Contact your host and ask them to:
- Whitelist the ModSecurity rule that's firing for the upload request, and
- Confirm that
admin-ajax.phpis not being blocked or rate-limited for file uploads.
6. Make Sure You're Using a Supported Form Plugin
Big File Form Uploads currently integrates with Contact Form 7, Gravity Forms, Forminator, Fluent Forms (with Fluent Forms Pro), and Elementor (with Elementor Pro). Upload fields in other form plugins use their own upload process and won't inherit the Big File Uploads limit through this add-on.
A Quick Note on How Uploads Behave
When everything is configured correctly, large files upload in small chunks and the form won't submit until the upload finishes. If a submission seems to "hang" on a very large file, that's the uploader working through the chunks — give it time to complete rather than resubmitting.
Still Need Help?
If you've worked through these steps and your form still won't accept large files, reach out to our support team. Let us know which form plugin you're using, your maximum upload size, the file size you're testing, and any error message you see — that helps us pinpoint the issue quickly.