Base64 Encoder/Decoder

Tool Guide

About This Tool

Base64 Encoder/Decoder converts text or file content between Base64 encoding and plain strings — instantly. Base64 is one of the most common encodings in web development, used in image data URIs, JWT tokens, HTTP Basic Auth, and email attachments.

Core Features

1. Bidirectional: Encode text to Base64 or decode Base64 back to readable text.

2. Charset support: Handles UTF-8, GBK, and other encodings — correctly processes multi-byte characters including Chinese.

3. URL-safe mode: Produces URL-safe Base64 (replaces + with -, / with _) for use in URL parameters and JWTs.

How to Use

Step 1: Select Encode or Decode mode.

Step 2: Paste your text into the input box.

Step 3: Click Convert and copy the result.

Use Cases

API development: Encode credentials for HTTP Basic Authentication headers.

JWT debugging: Decode the header and payload of a JWT token to inspect its claims.

Image embedding: Convert small images to Base64 data URIs for inline HTML/CSS, reducing HTTP requests.

FAQ

Q: Does Base64 encrypt data?

A: No — Base64 is an encoding format, not encryption. Anyone can decode it. Use AES or RSA if you need actual encryption.

Q: Does encoding increase data size?

A: Yes — Base64 increases data size by approximately 33% (every 3 bytes become 4 characters).