What does Flatten PDF do?
Flatten PDF is a free online tool that can rewrite a PDF with Ghostscript; check forms and annotations afterward. The PDF result from Flatten PDF is a separate copy to inspect before you use it elsewhere. One possible use is filled forms prepared for visible review.
Flattening rewrites a PDF through Ghostscript into a new PDF form. This can be useful when a reader has trouble displaying annotations or interactive content consistently.
Keep an editable source copy before trying it, because the new file is planned for a more fixed presentation. The exact treatment of forms, layers and annotations depends on the input and format change engine.
So you should check the elements that matter rather than assume every feature is flattened. A filled form should be saved before it is rewritten.
Some form values appear only when a viewer draws them. Compare the filled source and the new copy side by side.
Try a page with a checkbox and a page with free text. Keep the source if a field needs later correction.
Rewrite PDF forms and annotations online: steps
Before using Flatten PDF, decide what the new copy must contain and where it will be used. Save a filled and reviewed source, and note any form fields or annotations whose look must survive. Review the upload area and all values required by the current Flatten PDF form.
Choose the source
Read each filled value in the second viewer. For Flatten PDF, choose one source from your device. Keep a source copy for another attempt.
Review the form values
The Flatten PDF form has no extra task settings. Check the source in the file area.
Run the file task
Use Process Flatten PDF after checking the source and form values. Wait for the job to finish. An error means this attempt failed.
Save and check the output
Open the result in a second viewer and compare form values, comments, page backgrounds and links. Store the output on your device. Name this copy separately from the original.
Rewrite PDF: uses for Flatten PDF
Flatten PDF can help with annotation display problems investigated in another viewer. It can also be used for files rewritten for a simpler presentation workflow. The PDF result from Flatten PDF must suit the intended reading or editing step, so keep the source until that check is complete.
- Filled forms prepared for visible review.
- Annotation display problems investigated in another viewer.
- Files rewritten for a simpler presentation workflow.
- Fixed copies created while keeping an editable original.
Formats and limits for Flatten PDF
The Flatten PDF form accepts PDF sources. Each Flatten PDF upload can be up to 300 MB, which equals 300 MiB. The allowed suffixes on the Flatten PDF page do not prove that a source has valid content inside it.
| Accepted formats | Maximum file size | Output |
|---|---|---|
| 300 MB per file (300 MiB upload limit) |
This rewrite does not certify that every interactive field or layer has been removed. It can also change fonts, clear areas and existing digital signatures.
How this tool works
Flatten PDF uses Ghostscript to handle the source on the server. The Flatten PDF request uses your chosen input rather than any local editing project left on your device. Check the PDF contents produced by Flatten PDF before treating them as ready for another app or reader.
For Flatten PDF, your browser uploads the source to our file-processing server. This is a server task, not local editing.
Files are due for deletion within 1 hour. Cleanup runs during normal service operation. Keep a local download for future use.
Flatten PDF questions and answers
If Flatten PDF gives an unexpected result, start by checking the source type and the values used in the form. Check the PDF contents from Flatten PDF as well as the filename or displayed message. For another result type, compare Flatten PDF with the separate tools described in these answers.
What matters when using Flatten PDF?
Check whether a comment's visible mark survives the rewrite. View that area at its intended display size. Note any differences that affect your purpose.
Why try Repair PDF?
Repair PDF offers another task beside Flatten PDF: attempt to rebuild a broken PDF structure. Repair PDF returns PDF. The stated PDF output from Flatten PDF matches a listed input type for Repair PDF.
Why try PDF to PNG?
PDF to PNG offers another task beside Flatten PDF: convert all PDF pages to PNG images (zipped). PDF to PNG returns ZIP. The stated PDF output from Flatten PDF matches a listed input type for PDF to PNG.
Why try PDF to Grayscale?
PDF to Grayscale offers another task beside Flatten PDF: convert a color PDF to grayscale. PDF to Grayscale returns PDF. The stated PDF output from Flatten PDF matches a listed input type for PDF to Grayscale.
What if my PDF result does not open?
For a failed Flatten PDF result, first confirm that the download completed and that the viewer supports PDF. Try another local viewer for that format.
Record any error message for support. Keep private source material out of the report.
How do I report a problem with Flatten PDF?
Contact support with the Flatten PDF page name, source format and the error you saw. Mention any relevant form settings you chose. Do not send passwords or private attachments.