Flatten PDF
Turn a filled-in form into a plain PDF, with every answer fixed in place.
Runs in your browser. Your form is never uploaded.
Flattened PDF ready
What flattening changes, and what it leaves alone
A fillable PDF keeps each answer twice: as a value the form stores, and as an appearance — a small drawing of that value — that viewers put on the page. Flattening takes each field’s appearance, paints it into the page itself, and deletes the field. The answers look the same, but there is nothing left to click into, clear or retype.
Flattened
- Text boxes, including multi-line ones, with what was typed in them.
- Checkboxes and radio buttons, ticked or not, exactly as they were set.
- Drop-downs and lists, showing the choice that was made.
- Signature fields, which become a picture of the signature.
- Buttons such as “Print” or “Submit”, which become a drawing that does nothing.
Flattened only if you ask
- Comments and markup — sticky notes, highlights, underlines, freehand ink, text boxes added as comments, shapes and stamps. These are annotations rather than form fields, so by default they stay as they are, still editable and removable; the tool tells you how many there are. Tick the box to flatten them too: each one’s own drawing is painted into the page at exactly the size and place your viewer shows it, and a sticky note’s icon stays upright on a rotated page, as viewers draw it. The note’s text and replies are removed with it.
Never flattened
- Links, which keep working.
- Redaction marks that have not been applied. Each is just a box over content that is still in the file; painted in, the page would look redacted while the text underneath stayed selectable. Apply redactions in the editor that made them.
- Comments with nothing to draw — some older sticky notes carry no picture of themselves, leaving each viewer to invent one — and comments that are hidden or set to show only when printed. These stay as annotations.
- Hidden fields, used by some forms for calculations. They were never visible, so they are removed rather than drawn.
- Dynamic XFA forms, a format made by Adobe LiveCycle whose fields exist only inside Adobe’s own software. If a file shows “Please wait…” in most viewers, it is one of these, and it has to be printed to PDF from Adobe Reader instead.
When the answers would otherwise change
Some viewers save what you typed without redrawing the field, leaving a note asking the next viewer to do it — which is why the same form can show different answers in different apps. When a form carries that note, every field is redrawn from its saved value before it is flattened, so the flattened page shows what was actually entered. Redrawing uses a standard font, so the lettering may differ slightly from the form’s own.
Flattening is not redaction: the answers are still text that can be selected and copied. To stop a filled form being edited and also keep it private, flatten it and then add a password with Protect PDF.
Frequently asked questions
What does flattening a PDF do?
It turns the fillable form fields — text boxes, checkboxes, radio buttons and drop-downs — into ordinary page content. What you typed and ticked stays exactly where it is, but it can no longer be edited, cleared or read differently by another viewer. The page looks the same; it just stops being a form.
Are comments, highlights and sticky notes flattened too?
Only if you ask. Comments, highlights, sticky notes, drawings and stamps added in a PDF reader are a separate kind of annotation from form fields, and by default they are left exactly as they were, still editable and removable. When a file has any, a checkbox appears to flatten them as well: each is painted into the page exactly where your viewer shows it, so it always displays and prints and can no longer be edited or hidden.
What happens to the text of a sticky note when it is flattened?
Only the note’s icon is painted onto the page. The text inside the note, and any replies to it, lived in the annotation, so they are removed with it — completely, not just hidden. If the note text matters, copy it out first or leave comments unflattened.
Is my PDF uploaded to flatten it?
No. The form is read and flattened inside your browser tab, and the result is handed back as a download. Filled forms are usually full of personal details — names, addresses, tax and account numbers — so nothing is sent anywhere.
Why does my filled form look different in another viewer?
A form field stores its value and, separately, a picture of how that value looks. Some viewers save the value without updating the picture, or redraw fields with their own fonts, so the same form can show different text in Chrome, Preview and Acrobat. Flattening settles one appearance into the page, which is why it is the usual step before sending or printing a filled form.
Can I undo flattening?
Not in the flattened file — the fields are gone and their contents are part of the page. Keep the original if you might need to change an answer later. Flattening also does not hide anything: the text is still there to be read and copied, it just cannot be edited as a field.
What happens to a digitally signed PDF?
Flattening changes the file, so a certificate-based digital signature will no longer validate afterwards, and the signature field becomes a picture of the signature. Flatten before signing, not after. A drawn or typed signature placed with a tool like Sign PDF is ordinary page content and is unaffected.
Why does it say a field cannot be drawn?
Flattening redraws fields with a built-in font that covers English and Western European letters. A field holding another script — Hindi, Bengali, Chinese — keeps the appearance it already has where there is one. Where there is none, flattening would replace the text with question marks, so the tool stops and names the field rather than damage it.