Base64 Encoder & Decoder
This tool lets you convert plain text into Base64 and decode Base64 strings back into their original readable form. Base64 is a binary-to-text encoding scheme commonly used to safely transmit data through systems that expect text-only input.
Encoding does not encrypt or secure data. It simply transforms it into a standardized ASCII representation that can travel reliably through URLs, HTTP headers, JSON payloads, or config files without being corrupted.
How Base64 Encoding Works
Base64 works by taking raw bytes from the input text and re-encoding them using a fixed set of 64 characters. Every three bytes of input data are represented as four Base64 characters, ensuring the output contains only safe, printable symbols.
Decoding reverses this process. The Base64 string is interpreted back into its original byte sequence and then rendered as text. If the input is malformed or incomplete, decoding may fail or produce unexpected results.
Inputs and Options Explained
The tool provides several options to control how Base64 strings are generated or interpreted, depending on where the output will be used.
- Mode — Switch between Encode (text to Base64) and Decode (Base64 back to text).
- Trim input — Removes leading and trailing whitespace before processing, which helps avoid accidental decode errors.
- URL-safe Base64 — Uses URL-safe characters (
-and_) instead of+and/. - Remove padding (=) — Omits trailing padding characters, often required for tokens or compact URLs.
- Wrap lines — Breaks long Base64 output into multiple lines for readability or legacy compatibility.
Examples and Edge Cases
If you decode a Base64 string that was generated using the URL-safe variant, the URL-safe option must be enabled to get correct results. Similarly, removing padding during encoding requires the decoder to handle missing padding gracefully.
Base64 output is often longer than the original text. This is expected behavior and a trade-off for safe transport, not a sign of inefficiency or duplication.
Who Should Use This Tool
This tool is useful whenever text or binary data needs to be embedded inside systems that are not binary-safe.
- Developers working with APIs, tokens, or headers
- Engineers debugging encoded payloads
- QA teams validating encoded test data
- Anyone inspecting Base64 strings in logs or configs
Related Concepts
Base64 is often confused with encryption or hashing, but it serves a very different purpose.
- Encoding vs encryption — Encoding is reversible and not secure; encryption is designed to protect data.
- Binary-safe transport — Ensuring data survives systems that expect plain text.
- URL-safe encoding — Variants designed for query strings and path segments.
If you are working with encoded JSON payloads, decoding them and then formatting the result using the JSON Formatter can make debugging easier. For inspecting encoded tokens and headers, the JWT Decoder is also commonly used alongside Base64 tools.