Flatten PDF Lock Content Permanently

Merge form fields, annotations and signatures into static page content. Make PDF non-editable. Free, no upload, no watermark.

✓ 100% Free🔒 Files Stay On Device✦ No Watermark

// Flatten Options

Flatten form fields

Form field values are baked into the page permanently

Flatten annotations

Comments, highlights and drawings become part of the page

Remove JavaScript

Remove any embedded scripts from the document

Strip metadata

Remove author, title and creation information

🔥

Drop your PDF here

or click to browse — up to 200 MB

0 / 1 filesMax 200MB per file

How to Flatten a PDF — Step by Step

Flattening a PDF merges all interactive form fields, annotations, and layers into a single non-editable page layer. This prevents further editing of form data and ensures the document looks the same in every PDF viewer.

Upload your PDF (typically a filled form or annotated document). Drop your file into the upload area above.
Choose your flatten options. Select which elements to merge — form fields, annotations, JavaScript, and metadata stripping.
Click Flatten. The PDF is processed entirely in your browser with no upload required.
Download the flattened PDF — form fields become static text. The visual appearance is identical but all interactive elements are permanently merged.

When should I flatten a PDF?

Flatten before sharing a completed form to prevent recipients from changing the answers. Flatten annotated PDFs before archiving to ensure annotations are permanently visible. Printers and archival systems often require flattened PDFs for reliable output.

Flatten PDF on iPhone and Android

Doclair works in mobile Safari and Chrome. Upload your fillable form, flatten it, and download the static PDF directly to your device.

Frequently Asked Questions

Flattening merges interactive elements — form fields, annotations, highlights, and comments — permanently into the page content. The result looks identical but contains no editable or removable layers.

Yes. When form fields are flattened, their current values are burned directly into the page as static text. Anyone viewing the PDF will see exactly what was typed, but they cannot change or delete it.

Often yes — removing interactive form structures, JavaScript, and annotation metadata can reduce size noticeably. However, if the PDF already had no forms or annotations the size change will be minimal.

No. Flattening is a one-way, permanent process. Once interactive elements are merged into the page content they cannot be separated again. Always keep the original file if you might need to edit it later.

Flattening will visually preserve digital signature appearances on the page, but the cryptographic signature data will be invalidated — signature validators will no longer show the document as signed. If legal validity matters, do not flatten the PDF.

No. Everything runs entirely in your browser using the @cantoo/pdf-lib library. Your file never leaves your device — not even to our servers.

Was this tool helpful?

How to Flatten a PDF — Step by Step

Upload your PDF (typically a filled form or annotated document). Drop your file into the upload area above.

Choose your flatten options. Select which elements to merge — form fields, annotations, JavaScript, and metadata stripping.

Click Flatten. The PDF is processed entirely in your browser with no upload required.

Download the flattened PDF — form fields become static text. The visual appearance is identical but all interactive elements are permanently merged.

When should I flatten a PDF?

Flatten PDF on iPhone and Android

Doclair works in mobile Safari and Chrome. Upload your fillable form, flatten it, and download the static PDF directly to your device.

Frequently Asked Questions

No. Everything runs entirely in your browser using the @cantoo/pdf-lib library. Your file never leaves your device — not even to our servers.