Free Online Base64 Encoder & Decoder
Convert text to Base64 or decode Base64 strings back to readable text in one click — encoding and decoding share a single interface with a quick direction toggle. UtilHub's Base64 converter handles full UTF-8 input, including emojis, accented characters, and CJK scripts that break simpler tools. Use it to embed images in HTML/CSS data URIs, build basic-auth headers, decode tokens from log files, or inspect mystery strings in configuration files. There is no file size cap and no upload — your data is encoded locally using the browser's native TextEncoder, so even sensitive payloads stay on your device. Free, instant, no signup.
How to use Base64 Encoder & Decoder
- Type or paste plain text in the left box — the Base64 appears on the right as you type.
- Or paste Base64 in the right box — it is decoded into the left box instantly, and invalid Base64 is flagged.
- Click "Copy" to send the Base64 to your clipboard, or "Clear All" to start again.
Features
- Two-way conversion — Encode plain text to Base64 and decode Base64 back to text in the same tool. Both boxes are live, so there is no direction to switch.
- True UTF-8 support — Multi-byte characters including emojis, Chinese, Japanese, Korean, Arabic, and accented Latin letters encode and decode correctly via TextEncoder.
- Real-time output — The result updates as you type — no "Convert" button to press, no round-trip to a server.
- 100% private, no upload limit — All processing runs locally in your browser. No file size cap; nothing transmitted, logged, or stored.
Frequently Asked Questions
What is Base64 encoding used for?
Base64 represents binary data as ASCII text using 64 safe characters. Developers use it to embed small images in HTML/CSS via data URIs, encode basic-auth credentials for HTTP headers, transmit binary payloads through text-only channels like email or JSON, and store binary assets directly in configuration files. It is encoding, not encryption — Base64 makes data text-safe, not secret.
Does this tool handle emojis and special characters correctly?
Yes. Many simple Base64 encoders mangle multi-byte input — emojis, Chinese, Japanese, Korean, Arabic, and accented Latin letters all become garbage. UtilHub uses the browser's native TextEncoder, which produces correct UTF-8 byte sequences before encoding, and TextDecoder on the way back. Round-tripping "你好 🌏 café" gives you exactly "你好 🌏 café".
Is my text safe when I encode or decode here?
Absolutely. Every operation runs locally in your browser using built-in JavaScript APIs (btoa/atob plus TextEncoder/Decoder). Nothing is uploaded, logged, or sent to a server. You can verify by disconnecting from the internet after the page loads — the tool continues to work. Safe for tokens, credentials, and internal data.