How to Flatten a PDF (Lock Forms and Annotations)

You filled a PDF form and emailed it — the recipient opened it and the fields were still editable (or rendered blank in their reader). Flattening prevents this: it merges interactive elements into the static page.

When to flatten

• After filling a form — so values are permanent and display everywhere.
• After signing — so the signature can’t be moved or deleted.
• Before archiving — a flat PDF renders consistently for years.

How to flatten a PDF step by step

1. Open Flatten PDF and select your file.
2. It detects form fields and annotations and shows what was found.
3. Choose what to flatten (forms, annotations) and download.

Tips

• Flatten a copy. Once flattened, fields are no longer editable — keep the editable original if you might revise it.
• Form values render blank in some readers until flattened — if a reviewer says “it’s empty,” flattening is usually the fix.
• Pair with Protect PDF if it also needs to be locked from opening.

Privacy

Processed in your browser, never uploaded. No signup, no watermark.

FAQ

Does flattening change appearance? It keeps what you see and removes interactivity.

Can I edit afterward? Not the flattened elements — that’s the point. Use the original to revise.

Flatten now with Flatten PDF.

Related articles