Encoding

Base64 Decode

Decode a Base64 string back to plain text. Useful for inspecting JWT payloads, decoding values from HTTP headers, or reading data URLs.

Tool Summary Answer Block

This tool accepts structured input and returns deterministic output in the browser with no server upload.

Tool name: Base64 Decode
Input intent: Provide source content to transform, validate, or analyze.
Output intent: Receive normalized output suitable for copy, reuse, or debugging.
Example input: SGVsbG8sIHdvcmxk
Example output: Hello, world

Base64 inputDrop file

Decoded text will appear here after you click Decode.

Plain text outputRead-only

Tool Introduction

Decode a Base64 string back to plain text. Useful for inspecting JWT payloads, decoding values from HTTP headers, or reading data URLs.

Tool Overview

Base64 is a reversible encoding that maps every 3 bytes of input to 4 ASCII characters. This tool reverses that mapping and renders the result as UTF-8 text. If the input contains characters outside the Base64 alphabet, or the length is wrong, decoding fails and the tool reports "Invalid Base64".

Use Cases

Use Base64 Decode when you need fast decode base64 back to readable text.
Handle encoding workflows directly in the browser with no install required.
Support SEO long-tail intent by covering quick checks, troubleshooting, and one-off conversions.

Input/Output Examples

Input Intent

SGVsbG8sIHdvcmxk

Output Intent

Hello, world

FAQ

What does "Invalid Base64" mean?+

The input contains characters outside the Base64 alphabet (A–Z, a–z, 0–9, +, /, =), or its length is not a multiple of four after padding.

Can it decode binary files?+

This tool decodes to UTF-8 text. Binary data (images, archives) will appear as gibberish; for those, use a desktop tool that writes the result to a file.

Does it support URL-safe Base64?+

It uses the standard alphabet. URL-safe Base64 replaces + with - and / with _ — convert those characters back before pasting.