Password Protect PDF vs Flatten PDF: which should you use?
Password protection controls who can open a file. Flattening controls what remains editable inside it — a distinction that matters when you send final documents out.
When to use Password Protect PDF
Choose Protect PDF when access itself must be restricted with a password and permission flags.
Add password protection to your PDF documents for secure sharing.
When to use Flatten PDF
Choose Flatten PDF when form fields, annotations and layers must be baked into the page so nothing can be altered or hidden.
Flatten PDF forms and annotations for secure, uneditable document submission.
The verdict
Restricting access: protect. Freezing content: flatten. Serious disclosure workflows use both.
Both tools run inside your session, are UK GDPR-aligned, and every uploaded file is purged within 1 hour under our non-persistence guarantee.
Frequently asked questions
- Does flattening remove hidden metadata?
- It fixes visible content; use the Metadata Scrubber for a forensic clean of embedded metadata.
- Can a flattened PDF still be signed?
- Yes — flatten first, then apply signatures so the signed state matches what the reader sees.
- Is flattening reversible?
- No, which is exactly why it is used for final versions. Keep your editable original.
Open Password Protect PDF · Open Flatten PDF · Browse all tools