Can I un-flatten a PDF?

No. Once field appearances are merged into the page, there's no interactive layer left to restore. Keep a copy of the unflattened version if you might need to revise the values later.

Does flattening change how the document looks?

It shouldn't — the field values are rendered in place exactly where the fields sat. What changes is behavior: clicking where a field used to be now does nothing.

Does flattening remove comments and sticky-note annotations?

No — this tool flattens form fields specifically. Comments, highlights, and other markup annotations are a different mechanism and pass through untouched.

Does flattening reduce file size?

Sometimes. Forms with heavy field definitions can come out smaller once the form structure is dropped. For deliberate size reduction, run the result through Compress PDF — both operations are lossless, so they stack safely.

Will flattening protect my document from all editing?

It prevents casual edits to form values, but a flattened PDF is still an editable file format in principle. To restrict opening entirely, encrypt it with the Lock PDF tool after flattening.

Flatten PDF

Flatten form fields and annotations into static content.

Drop PDF files here or browse

Max 100MB per file

About Flatten PDF

Flattening a PDF merges its interactive form fields into the underlying page content. After flattening, the values look exactly the same in a viewer, but they're no longer fields — they're ordinary page text that can't be clicked into, edited, or reset. The form becomes a document.

This matters whenever a filled-in form needs to be final. Send someone an unflattened form and any PDF reader will happily let them change the values — the amounts, the dates, the checked boxes. Flatten it first and what you wrote is what they get. It's the digital equivalent of writing in pen instead of pencil.

Convertora flattens entirely in your browser: the file's form definition is read, each field's appearance is stamped into its page, and the interactive layer is removed. Tax forms, applications, and signed agreements never touch a server.

How to use it

1Upload a PDF that contains filled-in form fields (up to 100 MB).
2Click Flatten. Every field's current value is drawn permanently into the page content and the interactive field is removed.
3If the file turns out to have no form at all, the tool simply re-saves it unchanged rather than failing.
4Download the flattened file, saved with a -flattened suffix.

Common use cases

Locking the values of a filled-out contract or application before sending it to the other party.
Finalizing a form filled with the Fill PDF Forms tool, which intentionally leaves fields editable.
Preparing documents for archival, where editable fields are a liability years later.
Stopping recipients from clearing or altering checkbox selections on a submitted form.

Frequently asked questions

Tips

The natural pipeline for paperwork: Fill PDF Forms → Flatten PDF → Lock PDF. Fill it, freeze it, protect it.
Flatten before merging filled forms into a larger bundle — merging can break form interactivity in messy ways, while flattened values always survive intact.

100% private — runs in your browser

Convertora processes everything on your device using JavaScript and WebAssembly. Files never leave your browser, are never uploaded to a server, and are never seen by us or anyone else. The moment you close the tab, the data is gone — there is no temporary cloud copy, no log entry, no retained backup.

Because the work happens locally, processing speed depends on your device — but there are no rate limits, no daily caps, and no file size restrictions beyond what your browser can handle in memory. No signup, no account, no payment. The tool works the same in incognito mode, on a corporate network, or after the page has loaded once, even with the network disconnected.