Base64 Decoder

Base64 Decoder reverses Base64 ASCII back into UTF-8 text or raw bytes preview—essential when log files show encoded blobs instead of readable JSON.

Local decoding keeps intercepted tokens and support ticket payloads off third-party decode websites that might log input.

Error messages embed Base64 error details—decode in-browser before forwarding to security review.

Email MIME parts arrive encoded—quick decode confirms attachment type before saving.

• Inspect Base64 JSON error bodies from API gateways
• Decode data URL prefixes to confirm MIME type
• Verify round-trip after Base64 Encoder tests
• Read legacy config values stored as Base64 strings
• Debug JWT payload segment after splitting on dots

1. 1Paste the Base64 string—include or exclude data URL prefix per tool hints.
2. 2Click Decode to view UTF-8 text or hex preview.
3. 3If output looks garbled, confirm URL-safe variant or missing padding.
4. 4Copy decoded text for further JSON formatting.
5. 5Clear panel when finished if content was sensitive.

• JWT payloads are Base64URL—JWT Decoder handles padding and JSON parse automatically.
• Garbled binary output may mean the source was image bytes—check hex or download blob in desktop tools.
• Whitespace in pasted strings breaks decode—trim lines first.
• Never decode untrusted executable content and run it—decode is inspection only.

• Invalid padding produces errors—fix = padding at string end when needed.
• Very long strings may hang low-end tabs briefly.
• Common mistake — decoding encrypted ciphertext expecting plain text: encryption is not Base64.