Flatten PDF — Lock Content as Images
Turn every page of a PDF into an image so text can't be copied and form fields or content can't be edited.
Flattening converts each page into a still image. The result looks the same, but no one can copy the text or change the content and form fields — useful when a document needs to stay exactly as it is before you send it.
How to flatten a PDF (3 steps)
- Open your PDF.
- Click flatten.
- Download the locked file.
What happens to the file when you flatten it
Each page is rendered as a high-resolution image (about twice its actual size) and then assembled into a new PDF with the same page size. Everything that used to sit in separate layers — text, form fields, comments, watermarks, signatures — is merged into one permanent image and can no longer be edited separately.
- Selectable text — becomes part of the image. It can't be selected or searched.
- Fillable form fields — the values you entered are printed onto the page permanently and can't be changed.
- Comments, highlights, and arrows — burned into the page and can't be removed.
- Signatures or stamps placed on top — become one with the document.
- Clickable links — disappear, leaving only the text.
- Hidden layers — only what is visible on the page is kept; hidden content does not carry over.
When to flatten, and when not to
- Do flatten a completed form you are sending, so the recipient sees your entries in any viewer. Some programs show filled-in fields as empty.
- Do flatten a file with a signature or stamp on it, if you don't want anyone to drag the signature out and reuse it elsewhere.
- Do flatten a document whose fonts break or disappear on other computers because they weren't embedded. Flattened, it looks the same everywhere.
- Do flatten files for systems that only accept image-based PDFs or can't handle form fields.
- Don't flatten documents the recipient needs to copy text from or search, because they won't be able to.
- Don't rely on it to hide confidential information. Text in an image can still be read by eye and recovered with OCR. To truly remove information, use Redact PDF.
Common uses
- Submitting an application or form you filled in online — so the person processing it sees every entry.
- Signed quotations or contracts — so no one can change the figures or move the signature.
- Files exported from design software where the fonts didn't come through — flattened, they look like the original on every device.
- Slides with animation steps or stacked layers — leaving only the final image of each page.
File size and quality
Because every page becomes an image, a text-only file that used to be very small will grow several times larger, while a file that is already scanned images stays about the same. The resolution is enough for reading on screen and printing at normal size, but text won't be as crisp as real text when you zoom in a long way. If the result is too large to send, run it through Compress PDF. Always keep the editable original, because flattening can't be undone.
FAQ
How is this different from adding a password?
A password controls who can open the file or what they are allowed to do. Flattening makes the content a permanent image, so even someone who can open it can't copy the text.
Will my filled-in form entries be kept?
Yes, all of them, and they can no longer be edited. That makes it a good final step before sending a completed form.
Does the file size change? Why did mine get bigger?
Text that was stored as characters becomes an image on every page, so text-only files get several times larger; scanned files stay about the same. You can compress the result afterwards.
Can a flattened PDF be un-flattened?
No. Text and form fields are merged into a permanent image, so always keep the original. MyPDF creates a new file and does not touch the original on your device.
Can I use flattening to hide confidential information?
No. Text in the image is still readable and can be extracted again with OCR. To actually remove information from the file, use the Redact PDF tool.