Flatten PDF
Permanently merge form fields and annotations into the PDF.
Drop a PDF to flatten forms and annotations
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Flattening...
Permanently merge form fields and annotations into the PDF.
or click to browse
The document never leaves your device — flattening happens inside this browser tab.
A filled PDF form is really two documents in one. There is the page you see, and there is a separate interactive layer holding the field definitions and the values someone typed into them. The reader composites the two when it draws the page.
That split is useful while a form is being completed and a liability once it is finished. The values can still be changed. Different readers draw fields slightly differently. Older software sometimes shows a field as empty when it holds a value. And some upload validators read the stored field values rather than what is displayed, which is how a form that looks complete gets rejected as blank.
Flattening resolves it by drawing each field's contents permanently into the page and removing the interactive layer. One document instead of two. What you see is now genuinely all there is, and it renders identically everywhere.
This is worth stating plainly, because it is where flattening tools most often go wrong: field values are baked into the page as vectors, not as a picture of the page.
So the flattened document keeps everything that made it a PDF. Text stays selectable, searchable and copyable — both the original page text and the values that were in the fields. Fonts stay embedded and sharp at any zoom. Images keep their original resolution. Vector artwork stays vector. Screen readers still work.
The crude approach is to render every page to a JPEG and reassemble the document from those images. It technically flattens, and it destroys the text layer, makes the document unsearchable, and usually makes the file bigger. That is not what happens here.
The tool is also forgiving about imperfect files: a form with a malformed or partial field definition still produces a clean static document rather than failing outright, so a form that other software chokes on still gives you a usable result.
Flattening is a finishing step. Fill the form with Fill PDF Form, add a signature with Sign PDF, then flatten — in that order, because flattening removes the fields you would otherwise still be using.
Fill PDF Form offers Save (Flattened) directly, which does the same thing in one step when you are filling and finishing in one sitting. This standalone tool is for the other cases: a form somebody else filled in and sent you, a document that has been through several hands, or a file you want to finalise without reopening the form editor.
Keep the editable version. Save an unflattened copy for your own records and flatten the one you send — next year's version of the same form is then a five-minute job rather than a fresh start.
Open the document and click on a filled-in value. If a cursor appears, or the value highlights as an input box, the document still has a live form layer and would benefit from flattening before it goes anywhere. If clicking selects the text the way it would on any ordinary page, it is already flat.
The other tell is printing. Print to PDF, or use your reader's print preview, and compare it with the screen. A form whose field appearances are out of step often prints blank where the screen shows values — the exact failure that flattening resolves, and one that is much better to discover now than after submitting.
Loading the file here also answers the question directly: the field count is reported as soon as the document opens, so a report of zero fields tells you there is nothing interactive left to bake in.
No — the values become page content and the interactive layer is removed, which is the entire purpose. Your original file is never modified, so keep the filled, unflattened copy if you may need to edit the values later. Flatten the copy you send.
Usually it shrinks slightly, because the form definitions are removed while the values are added as compact vector text. Flattening does not convert pages to images, so there is no size explosion — the significant growth people associate with flattening comes from tools that rasterise, which this does not.
Flattening rewrites the document, and any rewrite invalidates a certificate-based cryptographic signature — true of every PDF tool, since detecting change is what those signatures are for. So flatten first, then sign. For a visible signature, Sign PDF draws it into the page, and a document signed that way can be flattened freely.
Yes. The invisible text layer that OCR adds is page content, not part of the form layer, so it passes through untouched and the document stays fully searchable after flattening.
You get a cleanly rewritten static copy — useful in its own right for tidying a document's internal structure before archiving. The tool reports the field count when you load the file, so you will know which case you are in before running it.
No. Title, author, subject and keywords live in the document's properties rather than on the page, so they survive. Edit Metadata is the tool for reviewing and clearing those — worth doing before a document goes outside your organisation.
Unlock it first with Protect PDF, flatten, then re-apply the password with the same tool if the document still needs it.
No. The PDF is read, flattened and rewritten entirely inside this browser tab, then handed to your downloads. Since flattening is usually the last step before a completed form goes to a bank, an employer or a government portal, that matters — go offline first and it still works.
Privacy: Flattening renders pages through PDF.js and rebuilds the output with pdf-lib — all inside your browser. No upload, no server-side rendering.