Base64 Encoder & Decoder

Encode or decode a text payload

1. Choose Decode for encoded data or Encode for ordinary text. Paste the source into the input. Each operation handles one complete payload, not a separate entry on every line.
2. When encoding, choose Standard or URL-safe. Decoding recognizes either alphabet automatically and accepts omitted padding or correctly padded input.
3. Run the conversion, then copy or download the complete result. If conversion fails, read the error and check the original source; the tool does not return a partial result.

Base64, text and URL-safe output

Base64 represents bytes with printable characters. It is reversible encoding, not encryption or compression. Anyone with the encoded value can recover the bytes without a key.

This tool converts text through UTF-8, so letters, accents and emoji can be represented together. Decoding rejects bytes that are not valid UTF-8 instead of guessing a character set or inserting replacement characters.

Standard output uses plus, slash and any required equals-sign padding. URL-safe output replaces plus and slash with hyphen and underscore, and omits padding. The decoder accepts either format but does not mix their special characters in one payload.

Spaces and newlines in ordinary text are data when encoding. Whitespace around or inside an encoded payload is ignored only for the stated ASCII whitespace characters. Decoded text retains its original spaces and line endings in the logical result and download.

Check the conversion with small examples

Hello encodes as SGVsbG8=. Decoding that value returns Hello. Encoding a single space produces IA==, so trimming text first would change the result.

The emoji 😀 becomes 8J+YgA== in standard Base64 and 8J-YgA in URL-safe Base64. Both represent the same four UTF-8 bytes.

Zg and Zg== both decode to f. A partly padded value such as Zg= is rejected. A payload can also pass Base64 validation but fail UTF-8 decoding when its bytes represent something other than UTF-8 text.

Text conversion has a defined scope

Encode up to 256 KiB of UTF-8 text, or decode a payload representing up to 256 KiB of text. A separate editor limit also applies. This tool does not process files, guess legacy encodings, unpack data URLs or inspect whole JSON Web Tokens. Paste only the encoded payload for the text you want to read.

Download preserves the result bytes without adding a newline or byte-order mark; an existing leading mark remains data. Clipboard software can normalize line endings, and some control characters are not visible in the preview. Use the UTF-8 download when exact text bytes matter.

Calculated in your browser

Conversion runs in your browser without tool-added uploads or saved input history. Copy writes the current result to your clipboard only when requested, and Download creates a local text file. Normal site services and consent settings remain separate.