Base64 Encoder / Decoder
Encode and decode Base64 — text and files, URL-safe variant supported.
How to Use
- Paste text in the top box to encode. Paste Base64 in the output to decode.
- Toggle URL-safe variant if needed.
- Drop a file to encode binary.
Text / file
⌘
Or drop a file
Base64
About Base64
Alphabet
A–Z a–z 0–9 + / (URL-safe: - _)
Overhead
≈ 4 / 3 × input bytes
Padding
= used to reach 4-char boundary
Spec
RFC 4648
Frequently Asked Questions
URL-safe?
Standard Base64 uses "+" and "/"; URL-safe swaps them for "-" and "_". Padding "=" can also be dropped.
Size overhead?
Base64 is 4/3 the size of the original binary — expect ~33% growth.
Common Use Cases
Data URIs
Embed images in CSS / HTML.
JSON payloads
Ship binary in JSON text fields.
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