JWT Decoder
Use the fields above to transform, validate, or format input. Errors appear in the on-page alert when parsing fails.
Decode JWT
How it works
Parsing and encoding run entirely in JavaScript here—no server sees your pasted content unless a tool explicitly says it fetches remote data.
Edge cases
- Hidden whitespace or BOM characters can break otherwise valid input.
- Line-ending differences (LF vs CRLF) may affect strict comparisons.
- Large payloads are best tested in chunks to isolate the failing part.
Use this tool for
- Formatting or minifying snippets before pasting into a repo or ticket.
- Checking encodings (Base64, hex, URL) without third-party paste services.
- One-off developer checks during debugging.
Common questions
What should I double-check before trusting JWT Decoder?
Verify units, bases, and pasted text (hidden spaces or wrong line endings); then spot-check one example by hand if the answer must be exact.
Is anything I type sent to NexUtility servers?
Static assets load from the host once; your entries stay in the browser and are not sent to NexUtility for processing.
