# How long does it take to flatten a PDF?

_Updated July 2026 · Arthize · https://arthize.com/answers/how-long-flatten-pdf_

Most jobs to flatten a PDF finish in a few seconds; large or scanned files take a little longer. Flattening a PDF merges form fields, annotations and layers into the page, so nobody can change filled-in values and the file renders everywhere. It runs in your browser session, so there is no upload queue to wait behind.

## Answer

Most jobs to flatten a PDF finish in a few seconds; large or scanned files take a little longer. Flattening a PDF merges form fields, annotations and layers into the page, so nobody can change filled-in values and the file renders everywhere. It runs in your browser session, so there is no upload queue to wait behind.

## More about flatten pdf

Flattening bakes form fields and annotations into the page so they can't be changed.

It fixes forms that display differently in different viewers.

A flattened PDF is the safe way to share a completed form.

## How to flatten a PDF

1. **Open the flatten tool** — Sign in and open the Flatten tool.
2. **Add your PDF** — Upload a form or annotated document.
3. **Flatten** — Arthize bakes fields and annotations into the page content.
4. **Download** — Get a flattened, tamper-resistant PDF.

## FAQ

### How do I flatten a PDF form?

Flattening a PDF merges form fields, annotations and layers into the page, so nobody can change filled-in values and the file renders everywhere. On Arthize it's free with no watermark and processed privately.

### Why do my filled form fields disappear in some viewers?

Flattening a PDF merges form fields, annotations and layers into the page, so nobody can change filled-in values and the file renders everywhere. On Arthize it's free with no watermark and processed privately.

### Is flattening a PDF free?

Flattening a PDF merges form fields, annotations and layers into the page, so nobody can change filled-in values and the file renders everywhere. On Arthize it's free with no watermark and processed privately.