# Flatten a PDF

> Flatten a PDF so it can't be changed: turn filled form fields into page content, or flatten everything into images like a print. Free and private, in your browser.

Make filled forms and annotations a permanent part of the page before you send the file.

## Key facts

- **Price:** Free, no sign-up, no watermark
- **Upload:** Never: the file is processed on your device
- **Works on:** Any recent browser on a computer, iPhone, iPad or Android
- **Files:** Up to 400 MB per PDF on a computer, 150 MB on iPhone and iPad. Larger files depend on your device's memory.
- **Updated:** October 1, 2026

Choose Form fields to bake filled fields into the pages while keeping text sharp and selectable. Choose Flatten everything to redraw every page as an image, like printing to PDF: comments, drawings, fields and hidden layers all become a flat picture.

## How it works

1. Drop the PDF.
2. Choose Form fields or Flatten everything.
3. Select Flatten PDF and download the result.

## Supported files

Input: one PDF. Output: one PDF.

Up to 400 MB per PDF on a computer, 150 MB on iPhone and iPad. Larger files depend on your device's memory.

## When to use it

- Send a filled form that the recipient can't modify.
- Make sure comments and drawings appear on every reader.
- Remove the editable layer of a PDF before publishing it.

## Quality and limitations

- Form fields mode handles form fields only; comments and drawings stay as annotations (use Flatten everything for those).
- Flatten everything makes text unselectable and increases the size of text-only PDFs.

## Common issues

- **“No form fields found.”:** The PDF has no fillable fields. Use Flatten everything to flatten comments and drawings.
- **Fields look empty after flattening.** Fill the form first ([Fill PDF form](https://nimbopdf.com/fill-pdf-form/)), then flatten it.

## Private by design

This tool runs entirely in your browser with JavaScript. Your file is read and processed on your device and is never uploaded to a server. Closing the tab discards everything.

[See how it works, step by step](https://nimbopdf.com/how-it-works/)

## Frequently asked questions

### What does flattening mean?

It turns interactive parts of a PDF (fields, annotations) into ordinary page content that can't be edited.

### Can I unflatten a PDF?

No. Keep your original if you might need to edit it again.

### Is my PDF uploaded?

No. It is flattened in your browser.

## Related tools

[Fill PDF form](https://nimbopdf.com/fill-pdf-form/)[Sign PDF](https://nimbopdf.com/sign-pdf/)[Compress PDF](https://nimbopdf.com/compress-pdf/)[Edit metadata](https://nimbopdf.com/edit-pdf-metadata/)

## Guides

- [How to sign a PDF on iPhone (in seconds)](https://nimbopdf.com/how-to-sign-a-pdf-on-iphone/)
- [How to password-protect a PDF on iPhone](https://nimbopdf.com/how-to-password-protect-a-pdf-on-iphone/)

## Optimize

[Compress PDF](https://nimbopdf.com/compress-pdf/)[All PDF tools](https://nimbopdf.com/tools/)

---

Source: https://nimbopdf.com/flatten-pdf/ · Nimbo (English) · https://nimbopdf.com/llms.txt