Base64 Encode/Decode

Convert data to a Base64 string, and convert a Base64 string to data

Enter text

Features

Supports UTF-8 including Japanese

Accurately converts multibyte characters without garbling

Converts automatically as you type

Shows the result instantly, no button needed

Supports up to 1 million characters

Can batch-process long text and larger data

Strict Base64 validation

Shows an error for invalid strings to prevent misconversion

How to Use

1

Select encode/decode

Select the conversion direction with the top buttons. You can also swap input and output with the center arrow button

2

Enter text or Base64

Paste a string into the input field and it converts automatically. Click the sample to try it out

3

Copy or save the result

Copy to the clipboard with the copy button, or save as a text file with the download button

Use Cases

Embedding in data URI format

Base64-encode text such as SVG or CSS and embed it directly into HTML

Checking API response data

Quickly grasp the contents of tokens or attached data returned in Base64 during development

Generating a value for Basic authentication

Easily create an authentication string that combines a username and password

Verifying email content

Decode a MIME-encoded subject or body to investigate the cause of garbling

Safety and Privacy

Runs entirely in your browser

Your input data is processed only within your browser and is never sent externally.

Processing only in your browser

conversion is processed entirely within your browser, and input data is not sent to any server.

Communications encrypted with HTTPS

Page loading is also encrypted by TLS, and content cannot be read by third parties.

No transmission to third parties

Input content is not sent to external services such as ad networks or trackers.

No automatic saving of results

conversion results and input suggestions are not stored on the server.