Encoding & Decoding
Convert between text encodings: Base64, URL encoding, HTML entities, JWTs and more — instantly and entirely offline.
- Base64 Encoder / Decoder Encode text to Base64 or decode it back to UTF-8 text, entirely in your browser. URL-safe alphabet option, 76-column MIME wrapping and live byte counts.
- Base64 File Encoder Turn any file up to 10 MB into raw Base64 or a ready-to-paste data URI in your browser, or decode a data URI back into a downloadable file.
- HTML Entity Encoder / Decoder Escape and unescape HTML entities in your browser. Encode only the five unsafe characters or all non-ASCII text, as named or numeric references.
- JWT Decoder Decode a JWT header and payload in your browser and read exp, nbf and iat as plain dates with live expiry status. Decoding only — signatures are never verified.
- URL Encoder / Decoder Percent-encode text with encodeURIComponent or encodeURI, or decode it back — locally in your browser, with the exact position of any broken % escape.
Encoding rearranges bytes so they survive a channel that would otherwise mangle them; it is not encryption, and nothing here hides data from anyone who cares to decode it. Which converter you want depends on the byte problem in front of you. For arbitrary binary or text that has to ride inside JSON, an email header or a data URI, the Base64 Encoder & Decoder does the 3-bytes-to-4-characters transform and handles UTF-8 correctly, where the naive btoa call falls over. Turning a whole file into a data: URI — an icon inlined into CSS, say — is instead the job of the Base64 File Encoder.
When characters like &, < or a stray quote need to appear as literal text inside HTML, the HTML Entity Encoder & Decoder converts them to &, < and named or numeric references. For query strings and anything going into a URL, the URL Encoder & Decoder applies percent-encoding, so a space becomes %20 and reserved characters stop breaking the path. And to read the claims inside a token — the header, payload and signature split by dots — paste it into the JWT Decoder, which base64url-decodes each segment on your device.
Two guides go further. Base64 is not encryption draws the line between encoding, hashing and real encryption with a comparison table, and the JWT security guide explains why decoding a token is nowhere near the same as verifying it.