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How do I encode or decode Base64 online?

Paste any text and click Encode to convert it to a Base64 string, or paste a Base64 string and click Decode to get the original text back. This tool supports full Unicode (including emoji and non-Latin characters) and runs entirely in your browser with no server round-trip.

Encode text to Base64
Input
Hello, World!
Output
SGVsbG8sIFdvcmxkIQ==
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Base64 Encoder & Decoder

Encode and decode Base64 strings online. Fast and private.

Tips & Best Practices

Security Note

Base64 is encoding, not encryption

Base64 makes binary data text-safe — it provides zero security. Anyone can decode a Base64 string instantly. Never use Base64 to "hide" passwords, API keys, or tokens. Kubernetes Secrets store values as Base64, which misleads many developers into thinking they are encrypted.

Common Pitfall

Standard Base64 breaks URLs

The + and / characters in standard Base64 have special meaning in URLs and filenames. Use Base64url encoding (replaces + with - and / with _) for JWT tokens, URL parameters, and file names. Most languages have a dedicated base64url variant.

Pro Tip

Base64 increases size by ~33%

Every 3 bytes of input become 4 Base64 characters. A 1 MB image embedded as a Base64 data URI becomes ~1.37 MB in your HTML/CSS. For images over 10 KB, a separate file with proper caching is almost always better for performance than inline Base64.

Real-World Example

Data URIs skip an HTTP request but block rendering

Small icons (under 2-4 KB) as Base64 data URIs reduce HTTP requests and can improve initial paint. But Base64 strings in CSS cannot be cached independently and increase stylesheet parse time. The sweet spot: inline SVG for icons, external files for photos.

Frequently Asked Questions

How do I encode text to Base64?
Paste or type your text in the input field and select Encode mode. The tool instantly converts your text to a Base64 string using the standard RFC 4648 alphabet (A-Z, a-z, 0-9, +, /). DevBolt's encoder handles full Unicode including emoji, CJK characters, and diacritics by encoding to UTF-8 first. The output can be copied with one click. Base64 encoding is commonly used to embed binary data in JSON payloads, HTML data URIs, email attachments (MIME), and authentication headers like HTTP Basic Auth.
How do I decode a Base64 string?
Switch to Decode mode and paste your Base64 string. The decoder converts it back to the original text instantly. It handles standard Base64, URL-safe Base64 (using - and _ instead of + and /), and strings with or without padding characters (=). If the input is not valid Base64, the tool shows an error message. Decoding is useful for inspecting API responses, reading JWT payloads, examining email MIME content, and debugging data URLs in HTML and CSS.
What is Base64 encoding used for in web development?
Base64 converts binary data into ASCII text using 64 printable characters. In web development, it is used for embedding small images as data URIs in CSS and HTML (avoiding extra HTTP requests), encoding binary files in JSON API payloads, HTTP Basic Authentication headers (username:password), email attachments via MIME encoding, and storing binary data in text-only formats like XML or CSV. Base64 increases data size by approximately 33%, so it is best for small payloads. For large files, direct binary transfer is more efficient.
Is Base64 encoding the same as encryption?
No, Base64 is not encryption and provides zero security. It is an encoding scheme that converts binary data to text in a reversible way — anyone can decode a Base64 string instantly. Never use Base64 to protect passwords, API keys, or sensitive data. For actual security, use encryption algorithms like AES-256 or asymmetric encryption like RSA. Base64 is purely a data format conversion for transporting binary content through text-only channels.

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