Base64 Decode

Decode Base64 strings back to readable text, or encode text to Base64, and copy or download the result.

Input
Output
0 characters 0 lines

Base64 Decode

This tool decodes Base64 encoded strings back into readable text. It is useful when you need to inspect encoded values from API responses, email headers, data URIs, authentication tokens, or any system that transmits data in Base64 format.

The decoding runs locally in your browser. The Base64 string you paste into the editor is not uploaded, stored, or sent to a server, so you can decode sensitive values safely without leaving your workflow.

How to use

  1. Paste a Base64 encoded string into the input editor.
  2. Click Decode to convert it back to readable text.
  3. Check the output editor and status message. Invalid Base64 input is reported immediately when decoding fails.
  4. Use Copy for the clipboard, Download for a text file, or Clear to reset both editors.

What is Base64?

Base64 is a way to represent bytes as printable text. It uses letters, numbers, plus signs, slashes, and padding characters so binary data can travel through systems that expect ordinary text, such as JSON, HTML, email, configuration files, and command-line output.

Base64 is an encoding format, not encryption. Anyone can decode it if they have the string. It also increases the data size by roughly one third, so it is best for transport and embedding, not for compression or secrecy.

Input notes

Make sure the input is a complete Base64 string and does not include unrelated headers, labels, or extra text around the encoded value. The decoder will report an error if the input contains invalid characters or is malformed.

Example

A Base64 encoded string can be decoded back to its original text:

--- Base64 Encoded Input ---
SGVsbG8sIFdvcmxkIQ==

--- Decoded Output ---
Hello, World!

MCP integration

MCP (Model Context Protocol) lets AI agents and apps discover and run Coding.Tools utilities for repeatable conversions, formatting, hashing, and generation workflows.

MCP tool name: base64-decode

MCP endpoint: https://coding.tools/mcp

Call tools/list first. Each tool entry includes inputSchema, outputSchema, and examples so an AI agent or client can build valid arguments without guessing.

For tools/call, read result.content[0].text for the display value and result.structuredContent for machine parsing. Tool-level failures return isError: true; protocol failures return a JSON-RPC error.

Example tools/call request:

curl -s https://coding.tools/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json" \
  -H "MCP-Protocol-Version: 2025-06-18" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"base64-decode","arguments":{"input":"SGVsbG8gZnJvbSBDb2RpbmcuVG9vbHMgTUNQ"}}}'

Most text and data tools accept an input string plus optional options. Browser-only image tools are listed for discovery and return a web UI link when they need browser image APIs.