Developer Tool
🔐 Base64 Encoder / Decoder
Encode text or files to Base64, or decode Base64 back to text. Supports URL-safe mode and full Unicode. Everything runs in your browser.
🧠 How Base64 Works
- Every byte of data (text, image, file) is broken into 6-bit chunks.
- 6 bits = 64 possible values, mapped to A–Z, a–z, 0–9, +, and /.
- The encoded string is about 33% larger than the original because 3 bytes become 4 characters.
- Padding: if the input isn't a multiple of 3 bytes, one or two
=signs are added at the end. - URL-safe mode swaps
+→-and/→_so the string is safe in URLs and filenames.
Important: Base64 is encoding, not encryption. Anyone can decode it. Never use Base64 to protect passwords, tokens, or secrets. Use real encryption like AES instead.
💡 Common Uses for Base64
data:image/png;base64,... to avoid extra requests.username:password as a Base64 string.data: URLs without a server request.❓ Frequently Asked Questions
What is Base64?
Base64 is a way of encoding binary data as text using 64 printable ASCII characters (A-Z, a-z, 0-9, +, /). It lets you safely transmit binary data through systems that only handle text — like JSON, XML, email, or URLs.
Is Base64 encryption?
No. Base64 is encoding, not encryption. Anyone can decode it instantly. Never use Base64 to protect passwords, secrets, or sensitive data. Use real encryption like AES for that.
What is URL-safe Base64?
URL-safe Base64 replaces + with - and / with _, and drops padding equals signs. It's safe to use in URLs, filenames, and JSON Web Tokens. Standard Base64 uses + and / which need encoding in URLs.
Why does Base64 make data larger?
Base64 encodes 3 bytes of data into 4 characters, so it adds about 33% overhead. A 1 KB file becomes roughly 1.33 KB when Base64 encoded.
Does it support emoji and non-English text?
Yes. When UTF-8 mode is enabled (default), emoji, Chinese, Arabic, and any Unicode characters are encoded correctly.
Is my data uploaded to a server?
No. Everything runs locally in your browser. Your text or files never leave your device. No tracking, no ads.
❤️ Support Free Tools
This calculator is free forever. If it helped you, consider buying me a coffee.
☕ Buy Me a Coffee