How to flatten a PDF
- Add the PDFs you want to flatten.
- Choose what to flatten. Form fields turns filled-in answers into ordinary page content while keeping text selectable. Everything redraws each page as an image, removing every annotation, layer and hidden element.
- If you chose Everything, pick a quality — 150 dpi suits screen and normal printing.
- Press Flatten PDF.
About this tool
Flattening a PDF makes its contents permanent. Filled-in form fields stop being fields and become part of the page; with the stronger option, everything on the page becomes a single fixed image. This free tool does both in your browser.
The common frustration behind it is a form that will not stay filled in. You complete a PDF application, send it, and the recipient reports that the boxes are empty — or opens it in a different reader and sees your answers vanish or shift. That happens because the values live in an interactive layer that not every reader renders the same way. Flattening the fields writes the answers into the page itself, so the document looks identical everywhere and cannot be reset or edited by whoever receives it.
The stronger option is a blunt instrument with a specific use. Redrawing each page as an image discards annotations, comments, hidden layers, form logic and any content sitting outside the visible crop area. It is what you want after cropping something confidential out of a page, or when a document must be visually final. The cost is real: text stops being selectable and searchable, and the file usually gets larger. If you need the text back afterwards, OCR will recover it.
Frequently asked questions
- Why do my filled-in form answers disappear?
- They live in an interactive layer that some readers do not display. Flattening the form fields writes them into the page so every reader shows the same thing.
- Which option should I choose?
- Form fields, in almost every case — it solves the disappearing-answers problem and keeps the text selectable. Choose Everything only when annotations or hidden content genuinely must go.
- Does flattening make the file smaller?
- Usually not by much. Flattening form fields barely changes the size. Flattening everything usually makes it larger, because text is replaced by images.
- Can a flattened PDF still be edited?
- Not the parts you flattened. Those elements can no longer be edited as fields or annotations. Someone with a full PDF editor can still alter the page, so pair it with a password if that matters.
- My PDF has no form fields and the tool said so. What now?
- That message means there was nothing to flatten in the field sense. If your goal was to remove annotations or hidden content, switch to Everything.