Base64 Encoder
Encode any text string or file to Base64 format. Useful for embedding data in HTML, CSS, APIs, and data URIs.
Why use Base64 Encoding & Decoding?
Base64 converts arbitrary binary data into a safe ASCII string using only 64 printable characters. This makes it ideal for embedding images in HTML, passing data through systems that don't handle binary safely, and encoding credentials in HTTP headers. It is not encryption — anyone can decode Base64 — so never use it to "hide" sensitive data. See also URL encoding and HTML escaping in the developer tools category.
Bidirectional
Encode text or binary to Base64 and decode Base64 back to its original form — both in a single tool.
URL-safe mode
Standard Base64 uses + and / which break URLs. Enable URL-safe mode to replace them with - and _ for use in query strings and JWT tokens.
Binary-safe transport
Base64 ensures binary data survives transmission through text-only channels like email (MIME), JSON, or XML without corruption.
Base64 use cases
Base64 appears throughout the web stack in more places than most developers realise.
| Use case | Where you see it | Example |
|---|---|---|
| Email attachments | MIME encoding in SMTP | Content-Transfer-Encoding: base64 |
| Inline images (Data URIs) | HTML/CSS — embed images without extra requests | data:image/png;base64,iVBOR… |
| JWT tokens | Header and payload sections of JWTs | eyJhbGci… (URL-safe Base64) |
| HTTP Basic Auth | Authorization header encoding | Authorization: Basic dXNlcjpwYXNz |
| API keys in config | Kubernetes secrets, CI/CD env vars | echo "secret" | base64 |