PDF Tools
Flatten PDF
Make supported form fields non-editable and merge annotation appearances into page content.
Frequently asked questions
What does flattening a PDF mean?
Flattening merges supported interactive form fields and annotation appearances into fixed page content. It does not encrypt the PDF or prevent all future editing.
Can I flatten PDF form fields?
Yes. Supported text fields, multiline fields, checkboxes, radio buttons, dropdowns, list boxes, buttons, and signature-field appearances can be merged into page content where a usable appearance is available.
Can I flatten annotations and comments?
Annotations with usable appearance streams can be flattened. Links are preserved by default, and unsupported annotations are preserved and reported rather than silently deleted.
Will flattening remove editable fields?
Successfully flattened fields are removed as interactive form objects when that option is enabled. Unsupported fields remain unchanged.
Will the PDF still look the same?
The tool uses existing or regenerated appearances to preserve visible content as closely as possible without rasterizing whole pages. Complex or malformed appearances may vary.
Are hyperlinks preserved?
Clickable link annotations are preserved by default. You can change this option, although links without a usable visible appearance cannot be converted into fixed content.
Are bookmarks preserved?
Bookmarks and document outlines are not intentionally modified and are preserved where supported by the PDF library.
Does flattening secure a PDF?
No. Flattening is not encryption, access control, tamper protection, redaction, or legal certification.
Can flattening invalidate a digital signature?
Yes. Any modification to a certificate-signed PDF can invalidate its existing digital signature. The tool does not re-sign documents.
Can I flatten selected pages only?
Yes. Choose the first page, last page, a custom range, or selected page numbers.
Can I flatten a password-protected PDF?
Not currently. Unlock it first with FiloTool's Unlock PDF tool, then upload the unlocked PDF here.
Will text remain selectable?
Ordinary page text remains selectable because pages are not rasterized. Text originally represented only by a field appearance may become fixed vector page content.
Are uploaded files deleted?
Temporary files are deleted after successful download, cancellation, failure, timeout, or automatic expiry under the service cleanup policy.
What is the maximum supported PDF size?
PDF files can be up to 100 MB and 500 pages. Additional safety limits apply to field, annotation, output, and processing sizes.