How to Flatten a PDF Online
Make PDF form fields and annotations part of the page in three simple steps. No software installation or signup required.
Add Your PDF Files
Select one or more PDFs from your device. Enter the correct password if a file is protected.
Choose What to Flatten
Select form fields, comments and annotations, or both. Your choice is applied to every PDF in the workspace.
Flatten and Download
Click “Flatten PDF,” review the result, and download the finished file. Multiple results can also be downloaded together as a ZIP file.
How Does the PDF Flattener Work?
The CompressFly PDF flattener turns selected interactive elements into fixed page content. Flatten form fields to make completed values non-editable, flatten comments and annotations to fix highlights, stamps, markups, and visible signature annotations in place, or process both together. The tool does not convert the full PDF pages into images, and existing links remain active. You can flatten one PDF or several files in the same workspace. Everything is processed locally in your browser.
What "processed locally" means
- Your PDF files are not uploaded to a processing server
- Flattening takes place on your device
- PDF passwords are handled only in your browser
- The finished PDF or ZIP file is created locally for download
When to Flatten a PDF
Flattening is useful when filled fields or review markups should stay visible without remaining interactive.
Finalize a Filled PDF Form
Turn completed form fields into fixed page content before sending an application, agreement, or client form.
Make PDF Annotations Permanent
Fix comments, highlights, stamps, and markups in place so recipients cannot move or remove them as annotations.
Prepare an Annotated PDF for Printing
Keep review marks with the page when preparing proofs, handouts, or records for print.
Batch Flatten Multiple PDF Files
Apply the same flattening choice to several forms or annotated PDFs in one run.
Why Use This PDF Flattener?
Easy to Use
Prepare a completed PDF for handoff without learning a full editing suite. The focused tool makes finalizing form answers and review marks easier to manage.
A More Consistent Handoff
Flattened answers and annotations become fixed page content in the saved copy. Recipients can read them as part of the document rather than relying on active form fields or separate markups.
Fewer Accidental Field Changes
Completed form values can remain visible without staying editable as form fields. This is useful when a filled copy is ready to send and those answers should stay in place.
No Installation Needed
Finish the document in your browser without installing desktop PDF software. An occasional completed form does not need a separate editing application.
Free Without Signup
Finalize your PDF without paying for a subscription or opening an account. The flattener and download are available for free.
Private Form Handling
Completed forms can contain personal information. Your PDF stays on your device during flattening, with no document upload to a processing server.
Flatten PDF FAQ
What does flattening a PDF do?
Flattening turns selected interactive PDF elements into fixed page content. Form values, comments, highlights, stamps, markups, and visible signature annotations stay visible but can no longer be edited, moved, or removed as interactive objects.
How do I flatten a PDF online?
Flatten a PDF in three steps: 1. Add one or more PDF files. 2. Choose form fields, comments and annotations, or both. 3. Click “Flatten PDF,” then preview and download the result.
Can I flatten only the form fields or only the annotations?
Yes. The form-field and annotation options are independent. Select only the content you want to make permanent, or select both to flatten them together.
Does flattening make the entire PDF non-editable?
No. Only the form fields or annotations you select lose their interactivity. Other page content may still be editable in a capable PDF editor. Use the Protect PDF tool when you need password or permission controls.
Does flattening convert PDF pages into images?
No. This tool flattens the selected form fields and annotations without rasterizing each full page. The rest of the PDF page structure is retained.
Will links still work after flattening a PDF?
Yes. Existing PDF links are preserved and remain clickable in the flattened result.
Can I flatten multiple PDF files at once?
Yes. Add several PDFs and apply the same flattening options to all of them. Download each completed PDF separately or download all results together as a ZIP file.
Can I flatten a password-protected PDF?
Yes, when you know the correct password. The password and PDF are handled locally in your browser and are not uploaded to a processing server.
What happens to digital signatures when a PDF is flattened?
A visible signature annotation can be flattened into the page, but changing a digitally signed PDF may invalidate its cryptographic signature verification. Keep the original signed file if signature validation matters.