Utively Free Tool

Base64 Encoder & Decoder

Encode text or files to Base64 and decode Base64 strings back to plain text — instantly in your browser, nothing sent to a server.

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Encode → Base64

Decode ← Base64

Frequently Asked Questions

What is Base64 encoding?

Base64 is a binary-to-text encoding scheme that represents binary data using only 64 printable ASCII characters (A–Z, a–z, 0–9, +, /). It converts every 3 bytes of binary data into 4 ASCII characters, making binary data safe to transmit over text-based protocols like HTTP, email (SMTP), and XML.

When would I use Base64 encoding?

Common use cases include: embedding images directly in HTML or CSS as data URIs (data:image/png;base64,…), transmitting binary files in JSON or XML API payloads, encoding credentials in HTTP Basic Authentication headers, storing binary data in text-only formats like cookies or URL parameters, and embedding fonts in CSS stylesheets.

Is Base64 encoding secure or encrypted?

No. Base64 is an encoding scheme, not encryption. It provides zero security — anyone can decode a Base64 string instantly. Never use Base64 to hide sensitive data. For security, use proper encryption (AES, RSA) or hashing (bcrypt, SHA-256) instead.

Can I encode images to Base64?

Yes. Use the "Encode a file instead" option to select an image from your device. The tool reads the file and outputs its Base64 content, which you can embed in HTML as a data URI: <img src="data:image/png;base64,YOUR_BASE64">. This is useful for inlining small icons to reduce HTTP requests.

What is the size overhead of Base64?

Base64 increases data size by approximately 33%. Every 3 bytes of input becomes 4 ASCII characters of output, plus possible = padding. A 100 KB image becomes roughly 133 KB as Base64. For large files this overhead is significant, so Base64 is best suited for small assets.