Base64 encoder / decoder
Base64 represents binary data as ASCII safe for JSON, HTTP headers, and email. Encode UTF-8 text or small files to Base64; decode API payloads and JWT segments back to readable text — all locally without leaking credentials to a server.
How to encode or decode Base64
1. Choose encode or decode mode.
2. Paste input text or Base64 string.
3. Read output instantly.
4. Copy result to clipboard for config or debugging.
Base64 examples
Basic auth header
Encode "clientId:clientSecret" to Base64 for Authorization: Basic ... header (use HTTPS only).
Decode JWT payload segment
Middle part of eyJ... token decodes to JSON claims — pair with JWT decoder for full parse.
Embed small config
Encode ini snippet for environment variable transport.
When Base64 helps
• When debugging API auth and data URIs.
• When decoding error payloads from logs.
• When teaching how encoding works interactively.
Not encryption
Anyone can decode Base64 — treat encoded secrets as exposed if intercepted. Always TLS in transit.
Frequently asked questions
URL-safe Base64?
Replaces +/ with -_ and may omit padding — check API spec.
Padding equals signs?
Valid Base64 ends with = or == for alignment — include when decoding strict parsers.
Decode failed?
Input may have whitespace or wrong alphabet — strip newlines.
Unicode text?
Encode UTF-8 bytes, not UTF-16 — standard for web.
Images?
Use image to Base64 for full data URL workflow.