# Flatten PDF Documents

> Form fields, signatures, and annotations get baked into static page content via pdf-lib so downstream tools cannot edit or clear them — useful when filled values are sensitive (SSNs, payroll, signatures) and a server round-trip is a non-starter. The document outline and bookmarks survive; output bumps to PDF 1.5 only when the input contains non-flattenable transparency groups.


Live tool: https://lofttools.com/tools/pdf-tools/flatten-pdf

Category: PDF & Documents

## How it works

1. **Select PDF** — Drop a PDF with form fields or layers, or click to browse
2. **Flatten** — Form fields, annotations, and layers are merged into the page content
3. **Download** — Download your flattened PDF instantly

## FAQ

### What does flattening do?

Flattening converts interactive form fields and annotations into static page content that cannot be edited.

### Does this preserve bookmarks and form fields?

Form fields are intentionally flattened into static page content — that is the point of flattening. Bookmarks and the document outline are kept.

### What PDF versions are supported?

Flattening works on PDF 1.0 through 2.0. Output is bumped to at least 1.5 if the input used non-flattenable transparency groups.

## Tips

- **Form fields become permanent ink** — Filled-in values, signatures, and annotations bake into the page content so downstream tools cannot edit or clear them.
- **Document outline survives flattening** — Bookmarks and the document outline are kept; only interactive layers collapse into static page content. The PDF stays navigable.
- **Signed forms never upload** — Flattening runs locally via pdf-lib — useful when the field values are sensitive (signatures, SSNs, payroll) and a server round-trip is a non-starter.

## Privacy — what we do not do

This tool runs entirely in the browser via WebAssembly. Your file never reaches a Loft Tools server. Specifically:

- **No upload.** The file bytes load into the browser tab's memory and process on your own CPU. Open DevTools → Network and observe zero outbound requests carrying file data while Flatten PDF Documents runs.
- **No AI training on your file.** Loft does not train models. We could not train on a file we cannot see.
- **No content scanning.** No virus, copyright, or content-moderation pass against your file. The bytes are not accessible to us.
- **No server-side log of file contents, filenames, or EXIF metadata.** Cloudflare edge captures URL and truncated IP for abuse defense (standard CDN behaviour). Cloudflare Web Analytics records anonymous page hits, no cookies, no PII. Nothing about your file content reaches any log.
- **No retention.** Close the tab and the file leaves browser memory. No backups exist on our side because no copy ever existed on our side.
- **No account.** No email, no signup, no auth, no telemetry tied to you.
- **Offline-capable after first visit** (PWA). Once you've loaded a tool, it caches; later sessions work without internet. For high-sensitivity files, run the tool once online to warm the cache, then disconnect before processing.

Compare with upload-based services: each transmits your file to a processing server. Even over HTTPS, each has logs, retention windows, and subpoena exposure. Loft has none of these because the server architecture does not include your file.

## More

- All tools: https://lofttools.com/tools
- Category: https://lofttools.com/tools/pdf-tools
- LLM index: https://lofttools.com/llms.txt