What is Base64 encoding used for?

Base64 is used to encode binary or text data as a safe ASCII string for transport in contexts that expect text — such as HTTP headers, JSON values, email attachments, and data URIs for images.

Is Base64 a form of encryption?

No. Base64 is encoding, not encryption. The original data can be decoded by anyone with the encoded string. Do not use Base64 to protect sensitive data.

Why does my Base64 string end with = or ==?

Padding characters (= or ==) align the output to a multiple of 4 characters. They are part of the standard Base64 format and expected by most decoders.

Can I use this to encode images to Base64?

This tool handles text and UTF-8 input. For encoding image files to Base64 data URIs, use a dedicated file-to-Base64 converter or a command-line tool like the base64 utility on Linux/macOS.

What is the difference between Base64 and Base64URL?

Base64URL replaces + with - and / with _ to make the output safe for use in URLs and filenames. JWT tokens use Base64URL encoding for their header and payload sections.

Base64 Encoder & Decoder — Free Online Base64 Tool

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Base64 encoder decoder

About Base64 Encode / Decode

Convert text or binary data to Base64 encoding, or decode Base64 strings back to readable text — instantly in the browser without any server-side processing.

Last reviewed

June 23, 2026

Key Features

Encode plain text or data to Base64
Decode Base64 strings back to plain text
Fast browser-based processing without uploads
Handles UTF-8 and standard ASCII input
Copy-ready output with no account needed

How to Use Base64 Encode / Decode

1Choose encode or decode mode.
2Paste your text or Base64 string into the input.
3Run the conversion and review the output.
4Copy the result for use in your code, config, or workflow.

API authentication header example

Basic Auth headers require Base64-encoded credentials in the format username:password. Encode the combined string here and prefix the result with "Basic " to form a valid Authorization header value.

How It Works

The tool applies standard Base64 encoding (RFC 4648) to the input. Encoding converts bytes to a 64-character alphabet; decoding reverses the process to recover the original data.

Privacy Notes

Input is processed in the browser. Avoid encoding sensitive credentials, long-lived API keys, or private data through online tools.

Limitations

The tool handles plain text and UTF-8 input. Binary files such as images or PDFs cannot be pasted directly — use a file-based tool or command-line utility for binary Base64 encoding.

Frequently Asked Questions

Base64 encoder decoder

About Base64 Encode / Decode

Convert text or binary data to Base64 encoding, or decode Base64 strings back to readable text — instantly in the browser without any server-side processing.

Last reviewed

June 23, 2026

Key Features

Encode plain text or data to Base64
Decode Base64 strings back to plain text
Fast browser-based processing without uploads
Handles UTF-8 and standard ASCII input
Copy-ready output with no account needed

How to Use Base64 Encode / Decode

1Choose encode or decode mode.
2Paste your text or Base64 string into the input.
3Run the conversion and review the output.
4Copy the result for use in your code, config, or workflow.

API authentication header example

Basic Auth headers require Base64-encoded credentials in the format username:password. Encode the combined string here and prefix the result with "Basic " to form a valid Authorization header value.

How It Works

The tool applies standard Base64 encoding (RFC 4648) to the input. Encoding converts bytes to a 64-character alphabet; decoding reverses the process to recover the original data.

Privacy Notes

Input is processed in the browser. Avoid encoding sensitive credentials, long-lived API keys, or private data through online tools.

Limitations

The tool handles plain text and UTF-8 input. Binary files such as images or PDFs cannot be pasted directly — use a file-based tool or command-line utility for binary Base64 encoding.

Base64 Encode / Decode

About Base64 Encode / Decode

Key Features

How to Use Base64 Encode / Decode

API authentication header example

How It Works

Privacy Notes

Limitations

Frequently Asked Questions

1What is Base64 encoding used for?

2Is Base64 a form of encryption?

3Why does my Base64 string end with = or ==?

4Can I use this to encode images to Base64?

5What is the difference between Base64 and Base64URL?

Base64 Encode / Decode

About Base64 Encode / Decode

Key Features

How to Use Base64 Encode / Decode

API authentication header example

How It Works

Privacy Notes

Limitations

Frequently Asked Questions

1What is Base64 encoding used for?

2Is Base64 a form of encryption?

3Why does my Base64 string end with = or ==?

4Can I use this to encode images to Base64?

5What is the difference between Base64 and Base64URL?