Base64 Encode Decode Tool

Worked example

Example: encode a short UTF-8 string to Base64 for a test fixture in an API integration test.

When to use this

• You are debugging an API response or token claim.
• You need readable JSON or XML in a code review.
• You want a quick encode/decode without terminal tools.

Common examples

• UTF-8 email header value → Base64 for debugging MIME parts.
• Small JSON claim → Base64 segment inspection before JWT assembly.
• Data URL prefix stripped → decode image bytes from `data:image/png;base64,...` payloads.
• Small SVG icon → data URL for inline HTML email test.
• UTF-8 string with emoji → Base64 for API fixture matching production encoding.

Common mistakes

• Pasting production credentials into shared browsers.
• Assuming decoded JWTs are verified—decode is not signature validation.
• Formatting invalid JSON without running the validator next.

How it works

Encodes plain text to Base64 or decodes Base64 back to text on your device using standard encoding. Large inputs are processed locally.

Limitations

Results are based on the inputs you provide and may not cover every edge case. This tool is for general use and is not professional advice.

Privacy and file handling

Your image stays on your device and is not uploaded.