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Flatten PDF Online — lock form answers and comments into the page
Turn filled-in form fields, and comments if you want, into ordinary page content. The answers look exactly as they did, but nobody can click into a box and change them. See every page before you save.
- PDF files aren't uploaded to our server
- Form fields and comments
- Text stays selectable
- Image option for a full flatten
Flatten form fields and comments
Add a PDF, see what can be flattened on each page, choose what to lock in, then save a new copy.
Drop your PDF here
or browse — one PDF, any number of pages
What to flatten
Pages
Found in this PDF
Your pages
Dashed boxes mark what will be flattened. Click a page to see it full size.
How it works
The answer stays, the editable box goes
A form field is a box drawn on top of the page that a viewer lets you type into. Flattening draws what the box shows onto the page itself and removes the box.
What you can do
- Lock text boxes, check boxes, radio buttons, lists and signature boxes into the page, looking as they do now.
- Do the same with comments: highlights, sticky notes, stamps, text boxes and drawings.
- Flatten all pages or only the ones you type. A field that also sits on other pages stays editable there.
- Turn pages into images when everything, layers included, must become one flat picture.
What it doesn't do
- Protect the file. With Keep text selectable, the answers can still be copied, and any PDF editor can change page content.
- Apply redactions. A black box flattened onto the page doesn't remove the text under it.
- Keep a digital signature valid. Any change to a signed PDF makes the signature check fail.
- Flatten dynamic XFA forms made in Adobe LiveCycle, or open password-protected PDFs.
How to flatten a PDF in four steps
Add, choose, check, save.
Add your filled PDF
Drop the PDF onto the upload area, or click Select PDF. Fill the form first; flattening keeps whatever the fields show right now.
Read what was found
- Found in this PDF lists the fields, comments and links.
- It also warns about signatures and XFA forms.
Choose what and where
Tick form fields, comments or both, pick the pages, and choose Keep text selectable or Make pages images.
Dashed boxes on the page list show exactly what will be flattened.
Save and download
Click Flatten PDF. The preview is drawn from the saved file; rename it if you like and download it.
What to choose for your job
Common reasons to flatten a PDF and the settings that fit.
| Job | What matters | What to choose |
|---|---|---|
| Send a filled application or tax form | The answers can't be changed by clicking into a box. | Form fields, Keep text selectable, All pages. |
| Upload to a portal that rejects fillable PDFs | No form left in the file. | Form fields, All pages. Check Found in this PDF says nothing is left. |
| Print a form whose answers show blank | Every printer and viewer shows the values. | Form fields, Keep text selectable. |
| Share a reviewed copy with comments fixed in place | Highlights and notes can't be moved or deleted by clicking. | Comments and markup (and Form fields if any). |
| Merge layers or make a page look-alike copy | One flat picture per page. | Make pages images, 150 dpi for screen or 300 dpi for print. |
| Lock the first pages, leave a sign-off page fillable | Some fields stay editable. | Pages I type, for example 1-3. |
The details
What happens to each kind of item
So the saved file holds no surprises.
Form fields
Each field's saved look is drawn onto the page at the same spot, size and angle, then the field is removed from the form. Unticked boxes and empty fields keep their empty look.
Comments and markup
Highlights, notes, stamps and drawings are drawn the way they look now. A note's pop-up text is removed with it. Redaction marks are left alone, because drawing them doesn't remove anything.
Links and bookmarks
Links stay clickable in both modes, and bookmarks and document properties are kept. Pages you didn't pick aren't changed at all.
Hidden items
Fields and comments set to hidden are removed without being drawn, so the page looks the way it does on screen.
Fields without a saved look
Some forms leave drawing the values to the viewer. Those values are drawn first in Helvetica, which covers Latin letters only; a field it can't draw stays a field, and the result names it.
Make pages images
Each chosen page is drawn at the resolution you pick and saved as one JPEG picture, with the page size unchanged. Text can't be selected or searched afterwards, and the file is often larger.
When flattening doesn't come out right
Identify the problem, then use the matching fix.
"Nothing to flatten on the chosen pages"
The PDF has no fields there, or the answers are already part of the page, as in a scanned or printed form.
Check Found in this PDF. To flatten anyway, choose Make pages images.
A field was kept as a field
It had no saved look and its text uses letters Helvetica can't draw, such as Gujarati or Hindi.
Choose Make pages images, which draws what you see on screen.
Answers are in a different font
The form asked viewers to draw the values themselves, so they were drawn in Helvetica.
Save the form from the app it was filled in, then flatten that copy; or use Make pages images.
The signature now shows as invalid
A digital signature covers the exact bytes of the file, and flattening changes them.
Flatten first, then sign. Send the signed original if the signature must stay valid.
"This is a dynamic XFA form"
The form is built in XFA, which browser PDF libraries can't draw.
Open it in Adobe Acrobat or Reader and print it to PDF, then flatten that copy if needed.
A password-protected PDF won't open
Encrypted PDFs can't be rewritten by the in-browser PDF libraries.
Remove the password with Unlock PDF, then add the unlocked copy.
Flattening at the right moment
A working order that avoids the most common redo.
Keep the fillable original
Flattening is one way. Keep the original so you can correct an answer later.
Check the answers full size
Open each filled page in the full-size view and zoom in before you save; what you see is what gets fixed in place.
Flatten before you sign
Sign the flattened copy, so the signature covers the final file and stays valid.
Prefer Keep text selectable
It keeps the file small and searchable. Use images only when layers or odd fonts must be merged.
Remove private data properly
To hide information, redact it; flattening a black box over text leaves the text in the file.
Protect if it matters
Flattening isn't a lock. Use Protect PDF when you need a password or editing restrictions.
Flatten PDF questions
If something's not covered here, the troubleshooting section above likely has it.
What does flattening a PDF change?
Form fields and, if you choose, comments stop being separate items that a viewer lets you edit. What they show right now is drawn onto the page itself, so the answers look the same but can't be changed by clicking into a box. The rest of the page is not changed.
Can I flatten comments and highlights too?
Yes. Tick Comments and markup. Highlights, sticky notes, stamps, text boxes and drawings are drawn onto the page as they look now, and their pop-up text is removed. Links stay clickable, and redaction marks are left as they are.
Will the text still be selectable after flattening?
With Keep text selectable, yes: the page text and the flattened answers stay real text, so they can be selected and searched. With Make pages images, each chosen page becomes one picture and its text can't be selected.
Can I flatten only some pages?
Yes. Choose odd or even pages, or type numbers and ranges such as 1, 3-5, 8-. A field that also appears on a page you didn't choose stays editable on that page.
Is flattening a way to protect a PDF?
No. It stops casual edits in a PDF viewer, but anyone with a PDF editor can still change the page, and with Keep text selectable the answers can be copied. Use a password if the file needs protecting, and redact anything that must be removed.
What happens to a digitally signed PDF?
The signature's look is drawn onto the page, but the signature itself stops being valid, because any change to a signed file breaks the check. Flatten first and sign the flattened copy.
Is my PDF uploaded?
No. The PDF is opened, flattened and saved in your browser with pdf.js and pdf-lib; it is not uploaded to our server. Password-protected PDFs need to be unlocked first.