Flatten PDF form fields right in your browser
Flatten PDF form fields free in your browser. Make filled-in values permanent and non-editable, then download instantly. Private, no upload, no sign-up.
100% private — files never leave your deviceFlattens any interactive form fields so their values become permanent, non-editable content.
How to use
- Upload your filled PDF. Select or drag in a PDF that has interactive form fields with your values already filled in. It loads straight into your browser, nothing is uploaded.
- Flatten the form fields. Click flatten and pdf-lib bakes every field value into the page locally, turning fillable fields into fixed content.
- Download the flattened PDF. Save the locked copy to your device. The filled-in values are now permanent and can no longer be edited in a PDF reader.
Features
- Nothing leaves your device. The PDF is flattened entirely in your browser with pdf-lib, so sensitive forms are never uploaded to any server.
- Locks in your answers. Filled-in text, checkboxes and selections become fixed page content that recipients can view and print but cannot alter.
- Keeps text crisp. Flattening merges the form layer into the page rather than turning it into a flat image, so your content stays sharp.
- Free with no sign-up. Flatten as many PDFs as you like at no cost, with no account, email or watermark on the result.
- Instant, in-browser speed. Powered by pdf-lib, flattening runs locally and finishes in seconds with no upload or server wait.
When to use it
- Lock a completed application or onboarding form so the values cannot be changed before you submit it
- Finalize a filled contract or agreement so recipients cannot edit the entered details
- Send a confidential tax or medical form with answers fixed in place, without uploading it anywhere
- Prepare a fillable invoice or order form for printing so it looks identical everywhere
- Archive signed-off paperwork as a tamper-resistant, non-editable copy
Is it private?
Your PDFs are flattened locally in your browser with pdf-lib and are never uploaded.
Frequently asked questions
Is this PDF flattener really free?
Yes. Flattening PDFs is completely free with no sign-up, no account and no email required, and there is no watermark on the output.
Are my PDFs uploaded to a server?
No. Your PDF is flattened entirely in your browser using pdf-lib and is never uploaded. The file stays on your device the whole time, which makes it safe for confidential forms.
What does flattening a PDF actually do?
It takes the interactive form fields in your PDF, those fillable text boxes, checkboxes and dropdowns, and merges their current values into the page as permanent content. After flattening, the fields are no longer editable in a PDF reader.
Will I be able to edit the form after flattening?
No, and that is the point. Once flattened, the filled-in values are baked into the page and can no longer be changed in standard PDF software. Keep your original if you still need an editable copy.
Are there any file size or format limits?
The tool works with standard PDF files and runs locally, so there is no server-side upload cap. Very large PDFs depend on your device's available memory since all processing happens in your browser.
Will flattening change how my form looks?
No. Flattening renders each field exactly as it currently appears and fixes it in place, so the layout, fonts and values stay visually the same, just no longer editable.
Does it work if my PDF has no form fields?
Flattening targets interactive form fields. If a PDF has no fillable fields there is nothing to flatten, so the content is already fixed and the file is effectively unchanged.
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