X.509 certificate inspector
Load public PEM or DER certificates and choose an observation date. Inspect the issuer, subject, SAN, serial number, algorithms, dates and SHA-256 fingerprint.
- Runs in your browser
- No upload
- Check before download
Load public PEM or DER certificates and choose an observation date. Inspect the issuer, subject, SAN, serial number, algorithms, dates and SHA-256 fingerprint. Private keys are rejected. The date status does not prove trust, a valid signature, revocation status or hostname acceptance.
Method: ASN.1 DER / X.509; asn1js 3.0.10
Local processing
Input stays in your browser worker, without requests, storage or content telemetry. Original backups and explicitly revealed exports may contain secrets; keep them local.
Resource limits
Combined input ≤1 MiB; text ≤200,000 characters (XML 100,000); depth 32 / nodes 20,000 per document; at most 1,000 rows/operations; output ≤2 MiB; worker deadline 5 s. Cancel terminates the worker. These application bounds do not guarantee a total browser heap cap.
Up to 10 certificates; each DER up to 64 KiB, ASN.1 depth 32 and 2000 nodes.
Choose the profile and review diagnostics before using saved output. Editing, resetting or leaving cancels work and discards the preview. Save original backups separately; no source file is overwritten.
Original backup: 1048576 B / Inspect / generate
How to inspect this input
- Source
Load public PEM or DER certificates and choose an observation date. Inspect the issuer, subject, SAN, serial number, algorithms, dates and SHA-256 fingerprint. Private keys are rejected. The date status does not prove trust, a valid signature, revocation status or hostname acceptance.
- Declared profile
ASN.1 DER / X.509; asn1js 3.0.10
- Review and save
Choose the profile and review diagnostics before using saved output. Editing, resetting or leaving cancels work and discards the preview. Save original backups separately; no source file is overwritten.
- Original backup
Input stays in your browser worker, without requests, storage or content telemetry. Original backups and explicitly revealed exports may contain secrets; keep them local.
Questions about the profile
Declared profile
Load public PEM or DER certificates and choose an observation date. Inspect the issuer, subject, SAN, serial number, algorithms, dates and SHA-256 fingerprint. Private keys are rejected. The date status does not prove trust, a valid signature, revocation status or hostname acceptance. ASN.1 DER / X.509; asn1js 3.0.10
Local processing
Input stays in your browser worker, without requests, storage or content telemetry. Original backups and explicitly revealed exports may contain secrets; keep them local.
Resource limits
Combined input ≤1 MiB; text ≤200,000 characters (XML 100,000); depth 32 / nodes 20,000 per document; at most 1,000 rows/operations; output ≤2 MiB; worker deadline 5 s. Cancel terminates the worker. These application bounds do not guarantee a total browser heap cap. Up to 10 certificates; each DER up to 64 KiB, ASN.1 depth 32 and 2000 nodes.