Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 back to plain text. Also encode files as data URIs. Runs 100% in your browser — nothing is ever uploaded.
What Is Base64 Encoding?
Base64 is a method of encoding binary data as plain ASCII text using 64 characters (A–Z, a–z, 0–9, +, /). It's widely used to safely transmit binary data through systems designed to handle text, such as email, JSON APIs, and HTML attributes.
Common uses of Base64
Base64 is used to embed images directly in HTML or CSS as data URIs (avoiding an extra HTTP request), encode binary attachments in emails, pass data through URLs without breaking them, and store binary data in text-based formats like XML or JSON.
Frequently Asked Questions
No. Base64 is encoding, not encryption. Anyone can decode it instantly. Never use Base64 to protect sensitive data.
Yes, by approximately 33%. A 100KB image becomes roughly 133KB when Base64 encoded. This is a tradeoff worth making for small icons but not for large images.
Standard Base64 uses A–Z (26), a–z (26), 0–9 (10), + and / (2) = 64 characters, plus = for padding. URL-safe Base64 replaces + with - and / with _.