SAML Request/Response Decoder
Free SAML decoder. Base64-decode and inflate SAML AuthnRequest/Response XML, pretty-print it, and inspect Destination, Issuer, and StatusCode. 100% client-side.
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What is SAML Request/Response Decoder?
The SAML Decoder turns the Base64 (and DEFLATE-wrapped) SAMLRequest/SAMLResponse blobs from single sign-on traffic into readable, pretty-printed XML, and highlights the fields that matter when SSO breaks: Destination, Issuer, ACS URL, ID, IssueInstant, and StatusCode.
Key Benefits
- Handles both redirect (deflated) and POST (plain Base64) bindings.
- Instant field summary for fast SSO troubleshooting.
- Pretty-printed XML with clear indentation.
- Nothing is uploaded - decode production data privately.
- No signup and no installation required.
Common Use Cases
- •Debugging a failed SP-initiated or IdP-initiated SSO flow.
- •Comparing the Destination against the receiving endpoint URL.
- •Checking StatusCode values to classify login errors.
- •Teaching teammates how SAML bindings wrap messages.
How to Use the SAML Decoder
- Copy the SAML value: Grab the SAMLRequest or SAMLResponse parameter from a redirect URL or a hidden form field.
- Paste it in: Paste the Base64 blob into the input box - decoding starts immediately.
- Inspect the fields: Check Destination, Issuer, and StatusCode in the field summary for common SSO mismatches.
- Read the XML: Scroll the pretty-printed XML for attributes, conditions, and signatures.
Key Features
- Auto-detects deflated redirect bindings and plain Base64 POST responses.
- Pretty-prints SAML XML with clean indentation.
- Extracts Destination, Issuer, ACS URL, ID, IssueInstant, and StatusCode.
- Warns when trust-relevant fields like Destination are missing.
- Decoding runs locally - safe for production assertions.
- No signup, no upload, works offline once loaded.