Base64 Encode/Decode

How it works

In text mode, the tool uses TextEncoder to turn your string into UTF-8 bytes, then btoa with chunked conversion for large inputs. Decoding reverses the flow with atob and TextDecoder. File mode reads bytes from a selected file via the File API and encodes them locally.

Benefits

• Unicode-safe encode and decode for international text and emoji
• Text and local file input without server upload
• Chunked conversion handles larger strings reliably
• Copy, download, examples, and optional on-device history

Use cases

• Encode small JSON or config snippets for data URLs
• Inspect Base64 fragments from logs or API responses
• Convert a local file to a Base64 string for testing
• Verify UTF-8 round-trip behavior before integration work

Best practices

• Use text mode for strings and file mode for binary payloads
• Confirm whether your API expects standard Base64 or Base64url
• Do not treat Base64 as encryption for secrets or credentials
• Clear the workspace on shared machines after handling sensitive data

Common mistakes

• Expecting readable text after decoding binary Base64
• Mixing Base64url (- and _) with standard Base64 (+ and /)
• Forgetting padding characters when manually editing Base64
• Assuming Base64 hides sensitive tokens from others

Privacy

All encoding and decoding happens in your browser. Files are read from your device only and are never uploaded. Optional LocalStorage history stores inputs locally if you enable it—avoid saving secrets on shared profiles.