Base64 Encoder / Decoder

Encoding /base64

Free Base64 encoder and decoder for UTF-8 text. Encode or decode locally without altering the source input.

Transfer
Local only
Limit
5 MiB input
Source text stays unchanged if decoding fails.
Encoded
Encoded or decoded output will appear here.
Choose Encode or Decode. Output follows as you type. 1 line 12 B local only

How it works

Free Base64 encoder and decoder for UTF-8 text with local processing and strict validation.

Use it when a UTF-8 text value needs standard Base64 transport encoding or decoding.

Example

Encode “Recica Tools” as UmVjaWNhIFRvb2xz and decode it back to text.

Notes

  • This tool supports standard Base64 only. Base64URL and data URLs are intentionally rejected.
  • Decode accepts pasted wrapped Base64 text and restores missing padding when it is unambiguous.
  • If decoded bytes are not valid UTF-8 text, the tool fails clearly instead of guessing.

Constraints

  • Decoding accepts standard Base64 text and returns UTF-8 text.
  • Limit: 5 MiB input. Nothing is uploaded or silently truncated.

Common errors

  • Base64URL characters
  • Invalid padding
  • Decoded bytes that are not UTF-8

When to use it

Use it when a UTF-8 text value needs standard Base64 transport encoding or decoding.

Formats: Standard Base64, UTF-8 text.

Reference

RFC 4648 — Base-N encodings

Substantively reviewed .