Input (Base64url)

Output

Base64 URL Decoding Examples

Paste a Base64url string (using - and _, no = padding required) to decode it back to text. Example:

Decode a Base64url string

Base64url input:

Input

Decoded output:

Output

Click Sample above to load a Base64url example.

What Is Base64 URL Decoding?

Base64url is defined in RFC 4648 Section 5 as a URL- and filename-safe variant of Base64.

To encode text to Base64url, use the Base64 URL Encoder. For standard Base64 decoding, use the Base64 Decoder.

How to Use This Tool

1

Paste Your Base64url String

Paste the Base64url string into the left editor. Click Sample to load an example.

2

Read the Decoded Output

The right panel shows the decoded text immediately.

3

Copy or Download

Click Copy or Download. To encode, use the Base64 URL Encoder.

How Base64url Decoding Works

This tool performs three normalization steps before decoding:

Normalization steps

After normalization, the string is decoded with atob() and TextDecoder.

Frequently Asked Questions

Is my data private?

Yes. Decoding runs entirely in your browser.

Do I need to add = padding before pasting?

No. This tool automatically adds any missing padding.

Can I decode standard Base64 here?

Yes. For a dedicated decoder, use the Base64 Decoder.

Can I decode JWT payloads here?

Yes. Copy the middle part (payload) and paste it here to decode the JSON.

What if the output looks garbled?

The input may contain binary data. Use the Base64 to File tool to download the raw bytes.

Related Tools

Ver RFC 4648 Sección 5.