Base64 Encode / Decode
Encode plain text to Base64 or decode Base64 back to UTF-8 text instantly in your browser. Switch between standard and URL-safe variants, control padding behavior, ignore whitespace during decode, and process large input in a Web Worker.
Base64 Encode / Decode Use Cases
- Encode API credentials or test payloads to Base64 during development
- Decode Base64 snippets copied from logs, headers, or debugging tools
- Switch quickly between standard and URL-safe Base64 variants
- Normalize messy Base64 input with whitespace and missing padding
Base64 Encode / Decode FAQ
Is my Base64 input sent to a server?
No. All Base64 encoding and decoding runs entirely in your browser. Your data never leaves your device.
What is the difference between standard and URL-safe Base64?
Standard Base64 uses + and /, while URL-safe Base64 uses - and _. URL-safe output is preferred in JWTs, query parameters, and filenames where reserved URL characters can cause issues.
Can this tool decode Base64 with missing padding or line breaks?
Yes. The decoder can ignore whitespace and automatically restore missing padding when possible, making it easier to handle copied payloads from logs and tokens.
Can it handle large Base64 payloads?
Yes. Inputs larger than 500KB are automatically processed in a Web Worker to keep the interface responsive.