PDF Signature Structure Checker Online - Inspect Embedded Signatures
Inspect a PDF locally for signature dictionaries, ByteRange values and SubFilter identifiers without uploading it.
About this tool
The checker scans PDF source bytes for common embedded signature structures and reports their count and metadata. It explicitly does not perform certificate or cryptographic verification.
How to use
- Enter the requested details or choose a supported file.
- Use the local controls to create, inspect or convert the result.
- Review the preview before downloading, printing or copying it.
Features
- Detects ByteRange entries.
- Lists signature SubFilter values.
- Accepts local PDFs up to 20 MiB.
Common use cases
- Check whether a PDF appears to contain signature structures.
- Collect fields for further forensic review.
- Triage a document before using a full validator.
Common issues and tips
- Structure detection cannot prove signer identity, integrity or certificate trust.
- Compressed or unusual PDF structures can make text-pattern scanning incomplete.
Privacy
All data and files are processed locally in your browser and are not uploaded to Tools12345.
Frequently asked questions
Does it cryptographically verify signatures?
No.
What is the file limit?
20 MiB.
Is a detected structure proof of validity?
No.