Flatten PDF
Lock form fields and annotations into static content so the PDF looks the same everywhere.
100% in your browser — files never leave your device
Flattens interactive form fields (text inputs, checkboxes, dropdowns) into static content. If your PDF has no form fields, it will be re-saved with optimized structure.
Why flatten a PDF before sharing?
Interactive PDF forms are convenient for filling out, but they carry risk once distributed. Recipients can clear or change field values, different PDF viewers render form fields inconsistently, and some email gateways strip interactive elements entirely. Flattening resolves all of this by converting every field into ordinary static content — the values you entered become part of the page itself, as permanent as typed text.
This tool uses pdf-lib to read the PDF's interactive layer and merge it into the page content stream. The process runs in your browser — no upload required. After flattening, the resulting PDF is a clean, static document that renders identically in every viewer and is safe to share as a final record.
If you want to go further and prevent any modification, combine flattening with the Protect PDF tool to add password protection.
Frequently asked questions
What does flattening a PDF actually do?
Flattening converts interactive elements — form fields, checkboxes, dropdowns, text inputs — into static page content. After flattening, the values entered in the form become permanent visual elements and the fields themselves no longer exist as interactive objects.
Why would I want to flatten a PDF?
Flattened PDFs are more portable: some PDF viewers render form fields inconsistently, and some recipients may be able to edit or clear fields in a non-flattened form. Flattening locks in the current values and ensures the document looks the same everywhere.
Does flattening remove annotations?
The tool uses pdf-lib, which flattens interactive form fields. Standard visual annotations (like comments or highlights) may or may not be affected depending on how the PDF was authored. The intent is to make the document non-interactive, not to remove visible content.
What happens if the PDF has no form fields?
The PDF will be re-saved with an optimized structure. No visible content changes — it is effectively equivalent to running the compress tool.
Are my files uploaded?
No. Flattening runs entirely in your browser using pdf-lib. Your file never leaves your device.