Flatten PDF
Make form fields, comments and stamps part of the page, so nobody can change them. Your PDF stays in your browser.
Drop a PDF here
Or open an example (a filled-in Form W-9). Your PDF stays in your browser.
What it flattens
Form fields
Text boxes, check boxes, radio buttons, lists and signature fields are drawn as they show on screen, then removed, so nobody can change the values.
Comments and stamps
Highlights, stamps, drawings and other annotations are drawn into the page too, and links keep working. Flatten only the fields or only the annotations if you like.
A preview
See the flattened pages before you download them, drawn by PDF.js, the PDF viewer in Firefox.
Encrypted PDFs
A PDF that only restricts editing opens straight away. For one that needs a password to open, the tool asks for it.
Signatures and XFA forms
The tool warns you when a PDF is digitally signed, and tells you when a form is a dynamic XFA form, which only Adobe Acrobat and Reader can draw.
Private
The PDF is flattened by code running in your browser. Nothing is uploaded, so you can flatten confidential documents.
Filling PDFs from code?
DocSpring fills your PDF forms from JSON and flattens the PDFs it makes, so there's no separate step. Fields you want people to keep editing can stay fillable: Editable PDFs.
To go the other way, and turn a flat PDF into a form people can fill in, see Make a PDF fillable.
To see a PDF's form fields and how they're stored before you flatten it, open it in the PDF debugger.
The tool reads and writes PDFs with pdf-lib, and draws the preview with Mozilla's PDF.js.
Questions about flattening PDFs
More free toolsWhat does it mean to flatten a PDF?
Flattening makes a PDF's interactive parts part of the page. Each form field's value is drawn as text, a check box as its check mark, and a comment or stamp as it looks on screen, and then the fields and annotations are removed. The PDF looks the same, but nobody can change the values.
Is my PDF uploaded?
No. The tool runs in your browser and flattens the file there. Nothing from the PDF is sent to DocSpring or anyone else.
Why flatten a filled-in form?
So the values can't be changed after you send it, so it prints the same everywhere (some viewers and printers leave out form fields or draw them differently), and so it can be combined with other PDFs without fields of the same name sharing values.
Does flattening keep a digital signature valid?
No. A digital signature covers the file as it was signed, and a flattened copy is a changed file, so its signature no longer verifies, though it still shows on the page. The tool warns you when a PDF is signed: keep the signed original.
Can it flatten encrypted PDFs and XFA forms?
A PDF that only restricts editing opens straight away, and for one that needs a password to open, the tool asks for it. The flattened copy is saved without a password. Static XFA forms, as many government forms are, flatten like other forms. Dynamic XFA forms are drawn only by Adobe Acrobat and Reader, so print one to a PDF from there instead.
What is the tool built on?
It reads and writes PDFs with pdf-lib, an open source library, and draws the preview with Mozilla's PDF.js. Their licenses are on our open source licenses page.
Fill and flatten PDFs with an API
Upload a PDF form, send JSON, and get back the filled, flattened PDF. Test PDFs are free and unlimited.