What is Base64 encoding and how does it work?

Base64 is a binary-to-text encoding scheme that converts binary data into a safe ASCII string format using 64 characters (A-Z, a-z, 0-9, +, /). It works by taking 3 bytes of binary data and converting them into 4 ASCII characters, making it safe for transmission over text-based protocols like email, HTTP, and JSON.

How do I encode text to Base64 online?

Simply paste your text into the input field, select "Encode" mode, and the Base64 encoded result appears instantly. You can copy the output or download it as a file. This free online Base64 encoder works entirely in your browser with no server uploads.

How do I decode Base64 to text?

Paste your Base64 encoded string into the input field, select "Decode" mode, and view the original text instantly. The decoder handles standard Base64, URL-safe Base64, and automatically detects padding issues.

When should I use Base64 encoding?

Use Base64 for: embedding images in HTML/CSS as data URIs, encoding binary data in JSON/XML APIs, email attachments (MIME encoding), storing binary data in databases as text, encoding authentication credentials in HTTP headers, and transmitting files through text-only channels.

Is Base64 encoding the same as encryption?

No! Base64 is encoding, NOT encryption. Anyone can decode Base64 data without a key. Never use Base64 to protect sensitive information like passwords or API keys. For security, use proper encryption algorithms like AES-256.

Why does Base64 increase file size by 33%?

Base64 encoding increases size by approximately 33% because it represents every 3 bytes of binary data as 4 ASCII characters. This overhead is the trade-off for making binary data safe for text-based transmission. For example, a 1MB image becomes ~1.33MB when Base64 encoded.

What is URL-safe Base64 encoding?

URL-safe Base64 (also called Base64URL) replaces + with - and / with _ to avoid URL encoding issues. Standard Base64 characters + and / have special meanings in URLs. Use URL-safe Base64 for JWT tokens, URL parameters, and file names.

How do I encode an image to Base64?

Upload your image file using the file upload button, and the tool will convert it to a Base64 data URI string. You can use this string directly in HTML img tags or CSS background-image properties to embed images without separate file requests.

Why am I getting "Invalid Base64" decoding errors?

Common causes include: invalid characters (Base64 only uses A-Z, a-z, 0-9, +, /, =), incorrect padding (missing = signs), corrupted data, or extra whitespace. Valid Base64 strings must have a length divisible by 4 after removing whitespace.

Can Base64 encode Unicode and emoji characters?

Yes! This tool properly handles Unicode characters including emoji by first encoding them as UTF-8 bytes before Base64 encoding. When decoding, it correctly interprets UTF-8 sequences back to Unicode characters.

What is the maximum file size for Base64 encoding?

This browser-based tool can handle files up to several megabytes efficiently. For very large files (100MB+), consider using command-line tools like base64 on Linux/Mac or certutil on Windows for better performance.

Is my data secure when using this Base64 tool?

Yes! All encoding and decoding happens 100% in your browser using JavaScript. Your data never leaves your device or gets sent to any server. This makes it safe for encoding sensitive data like API responses or configuration files.

How do I use Base64 in JavaScript code?

In JavaScript, use btoa() to encode and atob() to decode Base64. For Unicode support, use: btoa(unescape(encodeURIComponent(str))) to encode and decodeURIComponent(escape(atob(str))) to decode. Modern browsers also support the TextEncoder/TextDecoder APIs.

What is the difference between Base64 and Base32?

Base64 uses 64 characters and is more compact (33% overhead), while Base32 uses 32 characters (A-Z, 2-7) with 60% overhead but is case-insensitive and avoids confusing characters. Base32 is preferred for manual entry like TOTP codes.

Can I use Base64 for API authentication?

Yes, HTTP Basic Authentication uses Base64 to encode username:password credentials in the Authorization header. However, always use HTTPS as Base64 is not encryption. Format: "Basic " + base64(username + ":" + password).

What is Base64 encoding and how does it work?

Base64 is a binary-to-text encoding scheme that converts binary data into a safe ASCII string format using 64 characters (A-Z, a-z, 0-9, +, /). It works by taking 3 bytes of binary data and converting them into 4 ASCII characters, making it safe for transmission over text-based protocols like email, HTTP, and JSON.

How do I encode text to Base64 online?

Simply paste your text into the input field, select "Encode" mode, and the Base64 encoded result appears instantly. You can copy the output or download it as a file. This free online Base64 encoder works entirely in your browser with no server uploads.

How do I decode Base64 to text?

Paste your Base64 encoded string into the input field, select "Decode" mode, and view the original text instantly. The decoder handles standard Base64, URL-safe Base64, and automatically detects padding issues.

When should I use Base64 encoding?

Use Base64 for: embedding images in HTML/CSS as data URIs, encoding binary data in JSON/XML APIs, email attachments (MIME encoding), storing binary data in databases as text, encoding authentication credentials in HTTP headers, and transmitting files through text-only channels.

Is Base64 encoding the same as encryption?

No! Base64 is encoding, NOT encryption. Anyone can decode Base64 data without a key. Never use Base64 to protect sensitive information like passwords or API keys. For security, use proper encryption algorithms like AES-256.

Why does Base64 increase file size by 33%?

Base64 encoding increases size by approximately 33% because it represents every 3 bytes of binary data as 4 ASCII characters. This overhead is the trade-off for making binary data safe for text-based transmission. For example, a 1MB image becomes ~1.33MB when Base64 encoded.

What is URL-safe Base64 encoding?

URL-safe Base64 (also called Base64URL) replaces + with - and / with _ to avoid URL encoding issues. Standard Base64 characters + and / have special meanings in URLs. Use URL-safe Base64 for JWT tokens, URL parameters, and file names.

How do I encode an image to Base64?

Upload your image file using the file upload button, and the tool will convert it to a Base64 data URI string. You can use this string directly in HTML img tags or CSS background-image properties to embed images without separate file requests.

Why am I getting "Invalid Base64" decoding errors?

Common causes include: invalid characters (Base64 only uses A-Z, a-z, 0-9, +, /, =), incorrect padding (missing = signs), corrupted data, or extra whitespace. Valid Base64 strings must have a length divisible by 4 after removing whitespace.

Can Base64 encode Unicode and emoji characters?

Yes! This tool properly handles Unicode characters including emoji by first encoding them as UTF-8 bytes before Base64 encoding. When decoding, it correctly interprets UTF-8 sequences back to Unicode characters.

What is the maximum file size for Base64 encoding?

This browser-based tool can handle files up to several megabytes efficiently. For very large files (100MB+), consider using command-line tools like base64 on Linux/Mac or certutil on Windows for better performance.

Is my data secure when using this Base64 tool?

Yes! All encoding and decoding happens 100% in your browser using JavaScript. Your data never leaves your device or gets sent to any server. This makes it safe for encoding sensitive data like API responses or configuration files.

How do I use Base64 in JavaScript code?

In JavaScript, use btoa() to encode and atob() to decode Base64. For Unicode support, use: btoa(unescape(encodeURIComponent(str))) to encode and decodeURIComponent(escape(atob(str))) to decode. Modern browsers also support the TextEncoder/TextDecoder APIs.

What is the difference between Base64 and Base32?

Base64 uses 64 characters and is more compact (33% overhead), while Base32 uses 32 characters (A-Z, 2-7) with 60% overhead but is case-insensitive and avoids confusing characters. Base32 is preferred for manual entry like TOTP codes.

Can I use Base64 for API authentication?

Yes, HTTP Basic Authentication uses Base64 to encode username:password credentials in the Authorization header. However, always use HTTPS as Base64 is not encryption. Format: "Basic " + base64(username + ":" + password).

Base64 Encoder/Decoder

simple

Encode and decode Base64 data instantly. Convert text, files, and images to Base64 format for embedding in HTML, CSS, JSON, and APIs. Supports URL-safe Base64 and handles Unicode characters.

Encoders & Decodersbase64encoderdecoderconvert

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How to Use

1Enter text or paste data to encode/decode
2Select "Encode" or "Decode" mode
3View the result instantly
4Copy or download the output

Examples

Encode Simple Text

Input

Hello, World!

Output

SGVsbG8sIFdvcmxkIQ==

Encode with Unicode

Input

Hello 🌍 World! こんにちは

Output

SGVsbG8g8J+MjSBXb3JsZCEg44GT44KT44Gr44Gh44Gv

Decode Base64

Input

VG9vbEZvcmdlIC0gRGV2ZWxvcGVyIFRvb2xz

Output

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