Flatten PDF
Turn form fields, signatures and annotations into part of the page.
or drop files anywhere on this page
Your files stay in this browser. Nothing is uploaded.
About Flatten
Flatten PDF makes the marks on a document permanent. Flatten only form fields turns fillable form fields into ordinary page content, and Flatten everything turns every page into a picture of itself, so that fields, comments and annotations can no longer be edited or removed and no text can be selected from the page.
Reach for it before sending a filled-in form or a finished document somewhere it should not be changed. Flattening is not redaction, since everything visible on the page stays visible, and once applied, flattening cannot be undone from within this tool, so keep the original.
How it works
- Add one or more PDFs. A file that will not open without a password needs that password typed beside its name before anything else.
- Under Choose an option, pick Flatten everything (the default) to turn every page into a fixed image, or Flatten only form fields to keep text selectable while baking in filled-in values.
- For Flatten everything, pick an Image resolution: 75, 100, 150 (the default) or 220 dpi. A higher dpi looks sharper but produces a larger file.
- Click Flatten PDF. In Flatten everything, the status line counts through the pages as they are rendered.
- Download the result. Each file keeps its original name, and several files come back in a ZIP.
What each mode changes and what it keeps
Flatten everything renders each page with pdf.js at the dpi you chose, saves it as a JPEG at 85% quality and places it on a new page of the same size. The output is a brand-new document made of those pictures and nothing else. Text, links, bookmarks, form fields, annotations and document properties are not carried over as objects. What you see on the page is what remains.
Flatten only form fields edits the original file instead. Every form field is redrawn from its current value and drawn onto its page as ordinary content, then the empty form structure is removed. Text stays real text, and the rest of the document, including bookmarks, links and any comments or highlights, is left as it was.
Neither mode keeps a cryptographic signature valid, because the file is rewritten either way.
Choosing between the two modes
Pick Flatten only form fields when the file is a real fillable form and you want a smaller file that stays searchable. The values people typed and the marks in checkboxes are baked in, and nothing is rasterized. If nothing seems to change, the marks are probably annotations, such as comments, stamps or a placed signature, rather than form fields. Only Flatten everything will fix those in place.
Pick Flatten everything when the page must look exactly as it does now on any device and you can live without the text layer. Start at 150 dpi, go up to 220 dpi if small print looks soft, or down to 100 or 75 dpi if the file is too large. If you need searchable text afterwards, run OCR on the flattened copy. That gives you recognized text, not the original.
Limits and things that go wrong
Nothing here caps the page count or the file size. The practical limit is your device, since Flatten everything draws the pages one after another in the tab.
- File size can move either way. Every page becomes a JPEG at a fixed 85% quality, so a page of plain text can grow while a page that was a large image can shrink. Image resolution is the only control you have.
- A large-format document at 220 dpi is the case most likely to slow the tab, because higher resolutions cost more time and memory.
- A file that needs a password to open is opened with the one you type, and the flattened copy is saved without it. Use Protect afterwards if it should stay locked.
- A file that opens freely but restricts printing or copying works in Flatten everything, but Flatten only form fields stops with a password message for it. Run it through Unlock first.
Frequently asked questions
Flatten everything rasterises each page into an image, so form fields, comments and annotations can no longer be edited or removed. It behaves like a printed-and-scanned copy. Flatten only form fields keeps the page as real, selectable text and just bakes in the values you filled into the form, removing the form's editability.
Use Flatten only form fields when you want a smaller file with selectable text and no editable form. Use Flatten everything when you need the page to look exactly as it does now, with no possibility of extracting or editing the underlying content.
No, not from within this tool. Keep a copy of your original file if there is any chance you will need to edit the form or extract the text again later.
Yes. The page becomes an image, so any text on it, whether typed originally or filled into a form, is no longer selectable, searchable or copyable, only visible.
Yes. After flattening, the document no longer has an editable form. The values you entered remain visible on the page.
Flatten only form fields usually changes little, since it edits the existing text and form objects in place. Flatten everything can grow or shrink the file noticeably, since every page becomes a JPEG image at the resolution you chose.
The flattened copy is saved without the password you used to open the original. Flatten everything builds a new file from pictures of the pages, and Flatten only form fields saves the file again, so neither keeps the old password or its restrictions. Use Protect on the result if it should be locked again.
No. Flattening fixes what is on the page in place and does not hide or remove any of it. Whatever is visible before you flatten is still visible afterwards.
Yes. Add the files, choose the mode once, and every file is flattened with the same settings. Each result keeps its original name, and the results come back together in a ZIP.
The choices are 75, 100, 150 and 220 dpi, and 150 is the default. Every page is saved as a JPEG at the same fixed quality whichever you pick, so the resolution alone sets the balance between sharpness and size. Choose 220 dpi if small print looks soft, and 100 or 75 dpi when size matters more.
Related tools
This tool ran entirely in your browser and nothing was uploaded. Your Recent files list keeps a copy of local files under 5 MB until you clear it. How your files are handled.