What is Base64 Encode/Decode?
Base64 encode/decode tool — convert text to and from Base64 format. Base64 uses 64 printable ASCII characters (A-Z, a-z, 0-9, +, /) to encode binary data. Common uses: URL parameter encoding, MIME email attachments, HTTP Basic Auth headers (`Authorization: Basic <base64>`), and embedding small images in CSS (`data:image/png;base64,...`). Encoded output is ~33% larger than input (every 3 bytes become 4 characters). Everything runs locally in your browser — your text never leaves your device.
▶Use Cases5 scenarios
- ◆Encoding HTTP Basic Auth headers (username:password)
- ◆Safely passing special characters in URL parameters
- ◆Embedding small images in CSS as data URIs
- ◆Encoding MIME email attachments
- ◆Decoding Base64 API responses during debugging
▶How to Use4 steps
- 1Choose "Encode" or "Decode" mode
- 2Paste your text in the input box
- 3See the result instantly
- 4Click Copy to grab the output
▶Features5 features
- ✓Real-time encode/decode
- ✓UTF-8 support
- ✓One-click copy
- ✓Browser-only processing
- ✓Free with no limits
▶FAQ7 questions
What is Base64 Encode/Decode?
An online Base64 encoder/decoder. Quickly encode or decode text right in your browser. No uploads, instant results.. Everything runs locally in your browser — no uploads.
What is the difference between this tool and base64-encoder?
This tool (base64) focuses on quick text encode/decode with a simple interface. The base64-encoder tool also supports image file to Base64 conversion. Both use the same Base64 algorithm (RFC 4648).
Why does Base64 output look bigger than input?
Base64 converts every 3 bytes into 4 characters, increasing size by ~33%. For example, 300 bytes become 400 characters. This is the necessary trade-off for text-safe transport.
Is Base64 encryption?
No. Base64 is encoding, not encryption. Anyone can decode it — it provides zero security. For confidentiality, use AES encryption over HTTPS.
Does it work with non-English text?
Yes. The tool uses UTF-8 encoding, so Chinese, Japanese, Arabic, emoji, etc. are all correctly encoded to Base64. Note: multi-byte characters produce longer Base64 output.
Is my text uploaded anywhere?
No. Everything runs locally in your browser. Your text never leaves your device.
What about + and / characters in URLs?
Standard Base64 is not URL-safe. Use the Base64URL variant (RFC 4648 §5): replace + with -, / with _, and strip trailing = padding.