Encoding and decoding
Text is processed in this browser and is not uploaded or saved.
Help & FAQs
Convert URL components, full URIs, Base64 and Base64URL locally. Choose the format and direction, compare the original with the actual result, then copy or download UTF-8 TXT.
How to use
- Paste text or an encoded value.
- Choose the format and encode/decode direction.
- Convert, review the result, then copy or download it.
Exact text encoding rules
URL component mode uses encodeURIComponent/decodeURIComponent. Full URI mode uses encodeURI/decodeURI and preserves reserved URI characters. A plus sign stays a plus sign; this is not application/x-www-form-urlencoded form decoding. Malformed percent escapes or invalid UTF-8 are rejected.
Base64 encodes UTF-8 text using the standard alphabet with required padding. Base64URL uses the URL-safe alphabet without padding. Decoding rejects whitespace, mixed alphabets, noncanonical trailing bits and invalid UTF-8 rather than replacing bytes. A UTF-8 BOM is retained. Data URL headers and arbitrary binary files are not supported.
Input: 100,000 UTF-16 units / 400,000 UTF-8 bytes; output: 300,000 units / 400,000 bytes. Expansion can exceed the output budget even when input is valid. Processing yields with 45-second checkpoints. Edits, cancellation or leaving invalidate tasks and download URLs. Text is not uploaded, persisted or included in events.
Common questions
Does this encrypt text or verify a JWT?
No. These are reversible text encodings without a key. This tool does not encrypt secrets, verify signatures, decode arbitrary binary files, or fetch and open URLs.