PDF editing & conversion
Why compressing a signed PDF can invalidate its signature
Preserve the original when a digital signature must remain verifiable.
A visible signature is not the whole signature
A signed PDF may contain validation data in addition to a visible stamp or handwritten-looking mark. A picture of that page can retain the appearance while losing the information used to verify the digital signature.
Know the processing method
FormFile's target-size compression rebuilds pages as images when it needs to reduce the document. Its password-based reconstruction also produces an image-based copy. Those workflows do not preserve digital-signature validation, editable fields or searchable text.
Check the portal's requirement
If the institution requires the original digitally signed document, do not substitute a flattened copy just because its file size is smaller. Look for an accepted original download or ask the receiving institution how to handle its upload limit.
Keep separate copies
Use a clearly different filename for any reference or image copy. Retain the original PDF without overwriting it. After any permitted modification, verify the document in a suitable PDF viewer rather than assuming that a visible signature means validation survived.
Ready to prepare your file? Use PDF target size and check the downloaded result.