Base64 Decoder

Base64 Input

0 characters

Base64 Input

0 characters

Decode Result

Number

Free online Base64 decoder to convert Base64 strings back to readable text or binary. Supports URL-safe decoding and automatic padding fixes. Perfect for API debugging and log analysis.

Base64 Encoder

Base64 Padding Management

Base64 to Text

JWT Decoder

Authentication Header Generator

JSON Compress

Use Cases

Decode Base64-encoded API responses and JWT tokens to view the original JSON or text content.
Restore readable text from Base64 fields found in server logs, error stacks, or database exports.
Recover configuration values and credentials stored in Base64 format during system migrations.
Troubleshoot and fix decoding errors caused by missing padding, URL-safe characters, or line breaks.

Features

Instant & Secure Decoding: Convert Base64 to plain text or binary locally in your browser with zero data upload.
Smart Error Correction: Automatically detects and fixes common issues like missing padding (=) and invalid whitespace characters.
Universal Compatibility: Supports standard Base64 (RFC 4648) and URL-safe Base64 variants used in web tokens and API parameters.
Developer Ready: Perfect for inspecting JWT payloads, decoding API responses, and troubleshooting log files.

How to Use

1.Paste your Base64 string into the input box.
2.The tool automatically detects the format and decodes it to plain text or binary.
3.Review the decoded result instantly and check for any format warnings.
4.One-click copy the output for further debugging, documentation, or analysis.

FAQ

How do I decode a Base64 string back to text?

Simply paste your Base64 content into the input box. Our tool instantly converts it back to the original readable text or binary data, making it perfect for viewing API responses and log fields.

Why is my Base64 decoding failing with an 'invalid character' error?

Common causes include missing padding characters (=), the presence of whitespace/newlines, or the use of URL-safe characters (- and _ instead of + and /). Our decoder automatically attempts to fix these formatting issues.

Can this tool decode URL-safe Base64 strings?

Yes. Many web APIs and JWT tokens use URL-safe Base64 encoding. Our tool supports both the standard RFC 4648 alphabet and the URL-safe variant, ensuring compatibility with modern web development workflows.

Is it safe to decode sensitive API keys or tokens here?

Absolutely. GeekFormat's Base64 decoder operates entirely on the client-side (in your browser). Your sensitive data, API keys, and tokens are processed locally and are never transmitted to or stored on any external server.