Flatten PDF Online
— turn fillable form fields into permanent, non-editable content
Upload a PDF with fillable form fields and flatten them into static page content — what was typed or checked stays visible, but the field itself is no longer editable.
This flattens form fields only. Comments, highlights, sticky notes, and other markup annotations are untouched and remain fully editable. This tool also doesn't merge PDF layers (OCGs) — if your document has no fillable fields, flattening it will look identical to the original.
Flatten your PDF form fields
Upload a PDF, preview its pages, choose a scope, and flatten the form fields.
Form fields only — not comments, highlights, or layers
Flattening converts fillable text boxes, checkboxes, radio buttons, and dropdowns into permanent page content. It does not affect markup annotations (comments, highlights, sticky notes) or PDF layers — those stay exactly as they were.
Drop your PDF here
or browse files
One kind of "interactive," not every kind
A PDF can have several different types of interactive content. This tool addresses one of them — fillable form fields — using pdf-lib's built-in form-flattening function.
What this tool does
- Converts text field content into permanent, non-editable text on the page.
- Converts checkboxes and radio buttons into their checked or unchecked appearance permanently.
- Converts dropdown selections into static text showing the chosen option.
- Removes the underlying fillable field objects entirely, so the form can no longer be filled or edited.
What it does not do
- Does not touch comments, highlights, or sticky notes — these remain fully visible, editable, and deletable.
- Does not merge or flatten optional-content layers (OCGs) — layered PDFs stay exactly as they were.
- Does not affect transparency, drawing markups (Ink), or stamp annotations.
- Won't visibly change a PDF that has no fillable form fields — there's nothing to flatten.
Three steps, no configuration needed
There's nothing to set up — the tool detects and flattens whatever form fields exist.
Upload your PDF
Drag it onto the upload area, or click Select PDF. Works best for PDFs with fillable form fields.
Preview the file
Once uploaded, a preview appears. Page through it to confirm it's the correct, fully-filled-out document before flattening.
Choose pages, then flatten
Pick All Pages, Current Page Only, or type specific pages, then click Flatten PDF. Only fields on your selected pages are converted to permanent content.
Keep the original too
Flattening can't be undone within this tool — hold onto your original, fillable PDF in case you need it later.
When flattening form fields is the right move
And when you'd need a different tool entirely for what you're actually trying to lock down.
| Situation | What you need | Is this the right tool? |
|---|---|---|
| A filled-out application form | Prevent the recipient from editing your answers after submission. | Yes |
| A signed contract with fillable fields | Lock in the completed field values before sending for signature or archiving. | Yes |
| Older PDF viewer compatibility | Make sure filled form data displays correctly in viewers with limited form support. | Yes |
| Locking in reviewer comments | Make highlights, sticky notes, or markup permanent and unremovable. | No — not supported |
| Merging design layers before print | Combine optional-content layers into one flattened visual. | No — not supported |
| A PDF with no form fields at all | Nothing to flatten — the file will come out unchanged. | Not applicable |
When something doesn't look right
What's actually happening, and the fastest way through it.
The file looks completely unchanged after flattening
Your PDF likely has no fillable form fields — there was nothing for this tool to flatten.
Expected behavior for non-form PDFs. If you need to lock in comments or layers instead, this tool can't do that.
Comments or highlights are still editable after flattening
This is expected — flattening only affects fillable form fields, not markup annotations.
There's currently no supported way to make annotations permanent with this tool.
Flattening failed with an error
Some PDFs have unusually complex or malformed form structures that pdf-lib can't process.
Try re-saving the PDF from its original source application, then upload it again.
A password-protected PDF won't load
Encrypted files can't be read by the in-browser rendering engine.
Remove the password with a PDF unlock tool first, then upload the unlocked copy.
File looks unchanged
Why: No fillable form fields to flatten.
Fix: Expected for non-form PDFs.
Comments still editable
Why: Only form fields are flattened.
Fix: Not currently supported.
Flattening failed
Why: Complex or malformed form structure.
Fix: Re-save from the source app.
Password-protected PDF won't load
Why: Encrypted files can't decode in-browser.
Fix: Unlock it first, then upload.
Flattening at the right moment
A working order that avoids the most common surprise.
Fill out the form completely first
Flatten only after every field has its final value — anything left blank stays blank permanently.
Confirm your PDF actually has form fields
If it's mostly comments, highlights, or a layered design, this tool won't do what you're expecting.
Keep the original fillable file
Flattening is one-way — store the pre-flattened version somewhere safe in case you need to make changes later.
Preview before and after
Check the field values look right before flattening, then confirm the flattened output matches what you expected.
Use Redact PDF for anything truly sensitive
If a field contains information you need permanently removed rather than just non-editable, flattening alone isn't the same guarantee.
Understand flattening limits
Flattening removes the original form-field interactivity, but it is not a security control. Use Protect PDF when you need password-based access or permission settings, and choose the appropriate protection for your document.
Flatten PDF FAQs
Start here if you're not sure whether flattening does what you're expecting.
What exactly does flattening change?
It converts fillable form fields — text boxes, checkboxes, radio buttons, dropdowns — into permanent, non-interactive page content, drawing whatever was typed or selected directly onto the page and removing the underlying fillable field. Text and images that were already static are untouched.
Will this make my comments or highlights permanent too?
No. Comments, highlights, sticky notes, and other markup annotations are a different part of a PDF than fillable form fields, and this tool does not touch them. They remain fully visible, editable, and removable after flattening.
Does this merge PDF layers?
No. This tool does not read or modify optional-content layers (OCGs). If your PDF uses layers, they remain exactly as they were before flattening.
My PDF looks completely unchanged after flattening — is that normal?
Yes, in two situations: if your PDF has no fillable form fields at all, or if you selected "Current page only" or specific pages that don't contain any fields. Flattening only affects form fields on the pages you select, so a document with nothing to flatten there will come out looking identical.
Can I flatten just one page instead of the whole document?
Yes. Choose "Current page only" or "Specific pages" under Apply to Pages. Fields that appear across multiple pages may require selecting every page where they occur; check the output before relying on the result.
Is flattening reversible?
No. Once a form field is flattened, it cannot be turned back into an editable field within this tool. Keep a copy of your original file if you might need the fillable version again.
Is it safe to upload my documents here?
Yes. Your PDF is processed locally in your browser and is not uploaded to our server. External page resources, such as fonts or JavaScript libraries, may still load over the network.