Flatten PDF
Bake form fields and annotations into the page permanently.
or click to browse — supports PDF files up to 100MB
How to use
- 1 Drop or click to upload your file
- 2 Adjust options if shown
- 3 Click Run Tool
- 4 Download your result instantly
- ✓ Files up to 1GB
- ✓ Unlimited jobs/hour
- ✓ Batch processing
- ✓ Priority support
Files are processed securely and permanently deleted within 1 hour. We never store, read, or share your documents.
Why this works
Bake form fields, signatures, and annotations into the page so they become permanent, non-editable parts of the document. Useful for finalising completed forms, signed contracts, and any PDF you don\u2019t want a recipient editing.
PDF supports two distinct content layers. The page content is what gets printed \u2014 text, images, graphics encoded directly into the page. The annotation layer is interactive \u2014 form fields a user can type into, signatures dropped on top, comment bubbles, highlight marks, sticky notes. Annotations sit on top of the page; in most PDF readers a recipient can modify or delete them.
Flattening merges the annotation layer into the page content. After flattening, what was a fillable form becomes a static page that shows the filled values; what was a draggable signature becomes a fixed mark on the page; what were editable comments become permanent ink. The recipient sees the same visual result \u2014 they just can\u2019t change anything.
Three common cases. Completed forms: someone filled out a fillable PDF (tax return, application, intake form) and wants to send it back to the originator without giving the originator the ability to change what was entered. Flatten the form before sending. Signed contracts: signature annotations should ideally not be movable; flattening locks the signature in place. Internal review documents: comments and markups from a review pass are now resolved; flattening turns them into permanent annotations or removes them entirely so the document reads as final.
Flatten options let you pick what to flatten. Form fields only preserves comments and signatures as separate layers (useful when comments still need to be visible/editable but form data should be locked). Annotations only preserves form fields (useful when forms still need filling but comments should be cleared/locked). Both is the right default for a truly final document.
After flattening, the PDF is smaller (annotation layer overhead is gone), opens faster (no interactive layer to initialise), and is incompatible with form-data extraction tools \u2014 if your downstream workflow involves extracting field values programmatically, do that before flattening, not after. Flatten is one-way: there\u2019s no \u201cunflatten\u201d operation.
How it works
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1Upload your PDFDrop the PDF with form fields, signatures, or annotations to lock.
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2Pick what to flattenForm fields only, Annotations only, or Both. Both is the right default for a truly final document.
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3Run the flattenPress Flatten. The job finishes in 2\u20134 seconds.
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4Download the locked PDFThe output looks visually identical to the original, but the chosen layers are now permanently baked into the page content.
Real-world uses
HR teams
Lock completed onboarding forms before filing in the employee record.
Real-estate agents
Flatten signed addenda so signatures can\u2019t be repositioned in transit to the title company.
Tax preparers
Finalise tax-return PDFs so clients can review without accidentally clearing entered values.
Reviewers
After review comments are resolved, flatten the document so comments can\u2019t be edited further.
Common questions
What\u2019s the difference between flattening forms and flattening annotations?
Form fields are the interactive boxes where someone types responses (tax-form fields, application fields). Annotations include signatures, comments, highlights, sticky notes, drawing marks. You can flatten either independently or both together. Both is the right default for finalised documents.
Will the document look any different after flattening?
No \u2014 visually identical. The difference is internal: what was an editable form field becomes a static text rendering of the same value; what was a movable signature becomes a fixed mark on the page.
Can I undo a flatten?
No. Flatten is one-way \u2014 once the annotation layer is merged into the page content, the original interactivity is gone permanently. Keep your unflattened original safe if you might need to re-edit form fields.
Will flattening reduce file size?
Modestly, yes. The annotation layer\u2019s overhead disappears. Typical savings are 5\u201320% of the original file size, depending on how much annotation content the document had.
Does flattening strip metadata?
Most of it, yes. Document metadata (author, edit history, comments-by-user attribution) generally clears as a side-effect of re-rendering. For guaranteed metadata cleanup combined with content stripping, run Flatten after Redact.
Should I flatten signed contracts?
Generally yes \u2014 it locks the signature in position and prevents a recipient from accidentally moving or deleting it. The exception: if your e-signature workflow uses cryptographic digital signatures (DocuSign, Adobe Sign), flattening can invalidate the certificate chain. In those cases let the signing service handle finalisation.