Base64 Encoder/Decoder

Encoding · Base64 · data URLs

Encode text to Base64 or decode Base64 back to text in your browser. Handy for data URLs, debugging Basic auth headers, and inspecting encoded config blobs — with a clear reminder that Base64 is not encryption.

What Base64 actually does

Base64 represents binary data using 64 ASCII characters (A–Z, a–z, 0–9, +, /, with = padding). It exists so binary can travel through systems that expect text: MIME email, XML/JSON string fields, and HTTP headers. Encoded output is about 33% larger than the input.

Anyone can decode Base64. It provides zero confidentiality. If you need secrecy, use real encryption and a proper key management story — not btoa.

How to use this tool

1. Paste plain text to encode, or paste a Base64 string to decode.
2. Run encode or decode and inspect the result.
3. Copy into a data URL, header, or config as needed.
4. For JWTs and some URL contexts, note Base64url uses - and _ instead of + and /, often without padding — different alphabet, same idea.

Common use cases

• Data URLs — data:image/png;base64,… for small icons in HTML/CSS (keep payloads small).
• HTTP Basic auth — Authorization: Basic base64(user:pass); decode to debug which identity was sent (still send only over TLS).
• API fixtures — some webhooks embed binary or protobuf as Base64 strings inside JSON.
• Config archaeology — quickly see what an encoded blob contains when docs are vague.

Example

Input:  DevToolBox
Base64: RGV2VG9vbEJveA==

Basic auth material:
  user:pass  →  dXNlcjpwYXNz
  Header:    Authorization: Basic dXNlcjpwYXNz

Standard vs URL-safe

FAQ

Related tools

URL Encoder Hash Generator JWT Decoder HTML Entities

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