Flatten PDF

About flattening a PDF

A fillable PDF has form fields: boxes you type into, tick boxes, drop-down lists. After you fill them in, the answers are still live — anyone who opens the file can change them, and some apps (phones, printers, older readers) do not show them at all.

Flattening turns each field into plain page content, exactly as it looks now. The answers can no longer be changed, and they show the same in every PDF reader and on every printer.

This tool flattens every form field in the PDF and tells you how many it found. If the PDF has no fields, it says so — there is nothing to flatten. Everything happens in your browser; the PDF is never uploaded.

Features

• Every field type — text boxes, tick boxes, radio buttons, drop-down lists, list boxes and buttons
• A count of what was flattened — for example "14 form fields flattened: 8 text boxes, 2 tick boxes…"
• Honest when there is nothing to do — a PDF without fields is reported as already flat
• Fixes fields with no saved look — some apps save the answer but not how it looks; those fields are drawn again
• Accents and other alphabets — Polish, Czech, Turkish, Greek, Russian, Vietnamese; Chinese, Japanese and Korean too
• Before and after preview of the first page with fields
• One click to download — the flattened PDF is ready as soon as the file is opened

What changes and what stays

• Changes: the form fields are gone. Their answers (and their boxes, if the form drew any) are now printed on the page.
• Stays: everything else — the page text, pictures, page size, links and comments.
• Text that was typed into a field can still be selected and searched after flattening, because it is drawn as real text. Answers in Chinese, Japanese or Korean that had to be drawn again are drawn as shapes, and cannot be selected.

To fill in a form first, use Fill PDF Form — it has a "Lock the answers" box that does the same as this tool in one step.

Common uses

• Send a final copy of an application, contract or tax form that nobody can edit
• Make answers show everywhere — some phone apps and printers ignore form fields
• Before merging or printing — tools that copy pages often drop the fields and lose the answers
• Archive a completed form exactly as it was filled in
• Before signing — flatten first, then add a signature with Sign PDF

Frequently asked questions

What does "flatten PDF" mean?

It means the form fields are turned into normal page content. The answers stay on the page, but they are no longer fields, so they cannot be changed or cleared.

Can a flattened PDF be unflattened?

No. Once the fields are flattened, the PDF does not know they were fields. Keep the original file if you may need to change an answer later.

The tool says my PDF has no form fields. Why?

Some PDFs only look like forms: the lines and boxes are printed on the page, and there is nothing to type into. Such a PDF is already flat. To write on it, use Add Text to PDF. A scanned form is a picture of a page, so it has no fields either.

Does flattening protect my PDF?

It stops casual changes to the answers, but anyone with a PDF editor can still edit the page. To stop people opening or changing the file, add a password with Protect PDF.

What about a signed PDF?

A digital signature checks that the file has not changed since it was signed. Flattening changes the file, so the signature will no longer show as valid. Flatten first, then sign.

Is my PDF uploaded?

No. The PDF is read and flattened in your browser, on your own device.

Good to know

• Hidden fields stay hidden — they are removed, not printed
• XFA forms (made with Adobe LiveCycle) cannot be read by browsers; open them in Adobe Reader and use Print to PDF
• A password-protected PDF must be unlocked first with Unlock PDF

How to use it

• Click Click to upload, or drop your filled-in PDF onto the box
• Read how many fields were found and flattened
• Compare the page before and after
• Click Download flattened PDF