Free tool
Base64 Encoder & Decoder
Encode text to Base64 or decode Base64 to text. Supports standard Base64 and URL-safe Base64URL encoding.
About Base64
Standard Base64: Uses A-Z, a-z, 0-9, +, / and = for padding.
Base64URL: URL-safe variant that uses - instead of + and _ instead of /. No padding.
Base64 encoding increases size by ~33% (3 bytes become 4 characters).
What is Base64?
Base64 is a binary-to-text encoding scheme. It represents binary data as ASCII characters so that channels built for text (email, JSON, URLs) can carry it.
Common use cases
- •Email attachments: MIME encoding uses Base64
- •Data URLs: Embedding images in HTML/CSS
- •API payloads: Encoding binary data in JSON
- •Basic authentication: HTTP Basic Auth headers
- •JWT tokens: Header and payload encoding
Base64 vs Base64URL
Standard Base64 uses + and / characters, which can cause issues in URLs. Base64URL replaces these with - and _, and omits padding, making it safe for URLs and filenames.
Size consideration
Base64 encoding increases data size by approximately 33%. Three bytes of binary data become four Base64 characters.
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