Encodingversion v1.0.0

Base64 Encoder / Decoder

Convert bytes to Base64 and back, over both RFC 4648 alphabets: standard + / and URL-safe - _. Text or files, byte-exact in both directions — non-ASCII input is encoded as its UTF-8 bytes, which is where the browser’s own btoa quietly gets it wrong.

Mode

Variant

Padding

auto means on for standard and off for url-safe — currently on, the convention each variant travels with (MIME and PEM pad; JWT and PKCE do not).

Input

0 bytes · UTF-8

Output

From the command line

The same URL answers a POST with the value alone. Encoding returns the string and one newline; decoding returns your bytes and nothing else, so a file survives the round trip byte for byte.

$printf 'hello' | curl -fsS --data-binary @- https://tools.primeforge.app/base64

$printf 'aGVsbG8=' | curl -fsS --data-binary @- 'https://tools.primeforge.app/base64?mode=decode'

$curl -fsS --data-binary @logo.png 'https://tools.primeforge.app/base64?variant=url'