Flatten PDF
Lock form fields and notes into the page.
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About Flatten PDF
Flatten PDF locks form fields and notes into the page. After flattening, your typed answers, comments and markups become a fixed part of the page, just like printed text. Nobody can click a field and change your answer. The tool runs in your browser, so your file is not uploaded.
Flatten a form after you fill and sign it, before you send it to an embassy, employer, bank or university. Some apps and portals do not show form fields correctly, and flattening helps your answers appear the same everywhere. It also keeps review notes in place when you share a marked-up file.
How to use Flatten PDF
- Upload your filled form or annotated PDF.
- Click to flatten the fields and notes.
- Download the flattened PDF.
Why use PDF Hydra
- Lock form answersTurn filled form fields into fixed text that cannot be edited.
- Keep notes in placeMake highlights and comments a permanent part of the page.
- Looks the same everywhereYour answers show correctly in any PDF viewer or upload portal.
- Private and freeFlattening happens in your browser with no sign-up and no upload.
Frequently asked questions
What does flattening a PDF mean?
Flattening merges form fields and notes into the page itself. The content stays visible but can no longer be edited as a field or note.
Why should I flatten a form before uploading it?
Some viewers and portals hide or reset form fields. A flattened form shows your answers the same way everywhere.
Can I undo flattening?
Not in the flattened file. Keep a copy of the original if you may need to change your answers later.
Is my form uploaded?
No. The form is flattened in your browser and stays on your device.