Does flattening remove hidden metadata?

Field flattening removes form and annotation data. For document properties such as author and title, use the PDF Metadata Editor, which can strip them entirely.

Can I unflatten later?

No. Flattening is deliberately one-way, which is why the tool reminds you to keep the editable original.

My PDF has no form fields — is flattening pointless?

Not necessarily. Annotations, comments and stray interactive objects are still removed and the file is rewritten cleanly.

Are my files uploaded anywhere?

No. Every operation runs inside your browser tab using JavaScript and WebAssembly. Nothing is transmitted to MyToolyard or any third party, and nothing is stored after you close the tab.

Is there a file size or page limit?

There is no artificial limit — the practical ceiling is your device's memory. Files up to roughly 100MB are comfortable on a modern laptop; very large scanned documents are best processed in smaller batches.

Does it work on a phone or tablet?

Yes. The interface is fully responsive and touch-friendly. Very large documents will be slower on mobile because processing uses the device's own CPU and memory.

Flatten PDF

Lock filled forms, comments and annotations into the page so nobody can edit or un-fill them — or flatten everything to a fixed image.

No training on your data
Region: global

Drop a PDF to flatten

Click, drag or paste — flattening runs on your device

PDF & DocumentsOptimise & Secure

Flatten PDF — Overview

About this tool

What is Flatten PDF?

Flatten PDF turns interactive parts of a document — form fields, comments, highlights, stamps — into ordinary page content that nobody can edit, clear or re-fill.

Field flattening keeps the document lightweight and its text selectable and searchable, which is what you want when sending a completed application or signed form.

Full flattening re-renders every page as a fixed image at a resolution you choose, guaranteeing that no hidden layer, annotation or form value can be recovered.

What it does

What does Flatten PDF do?

Two levels of permanence, chosen per document:

Detects and reports how many AcroForm fields the PDF contains
Flattens filled field values into the page so they cannot be changed
Removes comments, highlights and other annotations
Optional full image flattening at 72–300 DPI
Keeps page size and orientation identical to the original
Plain-language warning that flattening is one-way

How to use

How to use Flatten PDF

1
Drop the PDF
Add the filled form or commented document. The tool reports the number of form fields it found.
2
Choose the level
Field flattening keeps text selectable; full flattening converts every page to an image so nothing survives.
3
Flatten and download
Export the locked copy and keep your editable original somewhere safe.

Good to know

Privacy & cost

This tool runs entirely in your browser. Nothing is uploaded, logged, or saved on our servers — safe for confidential or proprietary data.

Use cases & scenarios

Where it fits

Returning a completed form

Flatten before sending so the recipient cannot accidentally — or deliberately — change your answers.

Finalising a reviewed draft

Strip reviewer comments and highlights before the document goes to a client or a court.

Fixing forms that look empty

Some readers do not display filled field values. Flattening bakes them in so the document looks the same everywhere.

Value & benefits

Why people pick this tool

✓Free forever — no page caps, watermarks, sign-ups or premium tier
✓100% in-browser processing — your documents never touch a server
✓Works offline once the page has loaded, ideal for confidential files
✓No queues or waiting rooms — the work happens at the speed of your device

Frequently asked questions

FAQs

Final thoughts

The bottom line

A form is only finished when it can no longer be edited. Flattening is the step most people skip, and the one that stops a completed document from being quietly altered after it leaves your hands.