How to Use Flatten PDF
Upload your PDF
Drag and drop a file into the upload area, or click it to browse — it's processed on your device, never uploaded to a server.
Set your flatten options
Adjust the settings for this tool to get exactly the result you need.
Download the result
Click the action button to generate your file and download it immediately.
Features
🔒 Private by default
Your files are processed locally in this browser tab wherever this tool supports it — never uploaded to a server.
⚡ Fast, in-browser processing
Powered by pdf.js and pdf-lib running directly on your device — no waiting on a server queue.
🖥️ Works on any device
Use it from desktop, tablet or mobile — the tool interface adapts to your screen.
💸 No install required
It's a web tool — nothing to download or set up before you can use it.
FAQ
It permanently merges form fields and annotations into the page content, so they can no longer be edited as separate objects.
No — download stays as a separate file, but the flattened copy itself can't be un-flattened.