Flatten / Lock PDF
Flatten / Lock PDF is a free browser tool that lets you make pdf text non-selectable & non-editable. Pages are read and rewritten inside your browser with the PDF-lib engine, so the document never travels to a server and nothing is stored after you close the tab. It is used most by small firms handling client paperwork without a paid Acrobat licence. Handles standard PDF 1.4–1.7 files, including ones produced by Word, Google Docs, Canva and scanner apps. It stays free with unlimited use, and there is no watermark on anything it produces.
Key features
- Handles standard PDF 1.4–1.7 files, including ones produced by Word, Google Docs, Canva and scanner apps.
- Keeps the original page size, embedded fonts and image quality — no silent re-compression.
- Works on desktop, tablet and phone — no separate app to install.
- Built to do one job properly rather than twenty jobs badly.
How to use Flatten / Lock PDF
- Add your PDF: Drag the file onto the drop area, or click it to browse your device. Several files can be added at once where the tool supports it.
- Set the options: Choose page ranges, order or output settings. The preview updates so you can confirm before committing.
- Download the result: Press the action button and the finished PDF saves straight to your downloads folder.
Frequently asked questions
- Can Flatten / Lock PDF open a password-protected PDF? — Not while it is encrypted. Remove the password in the app that created the file first, then the tool can read it normally.
- Does Flatten / Lock PDF add a watermark? — Never. Flatten / Lock PDF produces a clean file with no branding, stamp or trial marking of any kind.
- Does Flatten / Lock PDF work offline? — Once the page has loaded, the processing itself runs locally — so a brief drop in connection while you work will not interrupt it.
- Does Flatten / Lock PDF upload my document anywhere? — No. Flatten / Lock PDF opens the PDF with JavaScript inside your own browser tab. The file is never sent to a server, which is why it also works with confidential contracts and medical or legal paperwork.