Base64 Encoder & Decoder
Encode UTF-8 text to Base64 or decode Base64 strings back to plain text with full Unicode safety and RFC 4648 URL-safe mode.
How the Base64 Encoder & Decoder works
Encode UTF-8 text to Base64 or decode Base64 strings back to plain text with full Unicode safety and RFC 4648 URL-safe mode. Below is the exact mathematical or algorithmic model used by this encoding utility, along with its key operating assumptions.
Converts UTF-8 byte stream via TextEncoder into 6-bit Base64 alphabet groups (A–Z, a–z, 0–9, +, / or URL-safe - and _).Step-by-step workflow
- Paste or type your input string, payload, or expression into the Base64 Encoder & Decoder editor.
- Your browser executes Converts UTF-8 byte stream via TextEncoder into 6-bit Base64 alphabet groups (A–Z, a–z, 0–9, +, / or URL-safe - and _). locally using native Web APIs without transmitting data over the network.
- Inspect validation diagnostics, byte/character metrics, or formatted output and copy the result in one click.
Worked example & key advantages
Encode API Basic Auth credentials or JWT header payloads into standard or URL-safe Base64 without exposing secrets over the internet.
Why use this Base64 Encoder tool
- Zero-telemetry local execution—safe for formatting production JSON payloads, tokens, regexes, and hashes.
- Uses standards-compliant browser APIs (RFC 8259 JSON, RFC 4648 Base64, RFC 4122 UUID, SubtleCrypto SHA-2, IANA tzdb).
- Instant feedback with byte-size metrics, line-number syntax diagnostics, and one-click clipboard copy.
Important Assumptions & Scope
- Uses TextEncoder / TextDecoder byte streams so multi-byte UTF-8 characters (like ₹) never throw DOMException.
Frequently Asked Questions — Base64 Encoder
Clear answers to common questions about methodology, edge cases, and privacy.
What is URL-Safe Base64?
Standard Base64 uses '+' and '/' which have special meanings in URLs. URL-safe Base64 (RFC 4648 §5) replaces them with '-' and '_' and strips '=' padding.
Is it safe to use the Base64 Encoder & Decoder with confidential production data?
Yes. The Base64 Encoder & Decoder executes entirely within your browser tab's memory using native JavaScript and Web Crypto APIs—no payloads, tokens, or strings ever leave your device.
Does the Base64 Encoder support UTF-8 and multi-line inputs?
Yes. All UtilAxis developer utilities handle multi-byte UTF-8 characters (including ₹, accented characters, and emojis) as well as multi-line payloads without truncation.