What is Base64?
A plain-English definition, and the tools that work with it.
Base64 is a way of encoding binary data (like an image or file) into plain ASCII text using 64 safe characters. It lets you embed or transmit binary content through systems that only handle text, such as email, JSON or data URIs.
- Base64 is encoding, not encryption: it's fully reversible and provides no security, only text-safe transport.
- Encoding inflates the size by roughly 33%, so it's used for small assets (icons, tokens), not large files.
- A common use is inlining a small image into HTML/CSS as a data URI so it doesn't need a separate request.
Tools for Base64
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Base64 Encoder
Encode text or any file to Base64 instantly: Unicode-safe, with a URL-safe toggle and one-click data URLs. Runs entirely in your browser, nothing uploaded.
Base64 Decoder
Decode Base64 back to text or a file instantly: Unicode-safe, auto-detects URL-safe input, sniffs binary data and offers a download. Runs fully in your browser, nothing uploaded.
Hash Generator
Compute MD5, SHA-1, SHA-256, SHA-384 and SHA-512 checksums of any text or file at once, generate HMAC signatures with your own key, and verify a download against its expected hash, all in your browser, nothing uploaded.
URL Encoder
Percent-encode text and URLs instantly: pick component mode for query values or full-URL mode to preserve structure, with a per-line batch switch. 100% in your browser, nothing uploaded.
Frequently asked questions
Related terms
- JSONJSON (JavaScript Object Notation) is a lightweight, text-based format for structured data, built from key–value pairs and lists. It's the standard way apps and APIs exchange data because it's easy for both humans and machines to read.
- SVGSVG (Scalable Vector Graphics) is an image format that describes graphics as mathematical shapes and paths rather than pixels. Because it's vector-based, an SVG stays perfectly sharp at any size (from a favicon to a billboard) and is usually a small, text-based file.
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