Base64 Encoder/Decoder

Encode text to Base64 or decode Base64 strings back to plain text. Fast, secure, and works offline in your browser.

Plain Text Input

0 characters

Base64 Output

0 characters

Auto ProcessAutomatically encode/decode as you typeURL SafeUse URL-safe Base64 encoding

Base64 Usage Tips

Base64 encoding increases data size by approximately 33%
Use Base64 to encode binary data for text-based protocols
URL-safe encoding replaces + and / with - and _ for safe URLs
Base64 is encoding, not encryption - don't use for security
Perfect for embedding images in CSS or HTML (data URLs)
Commonly used in email attachments and API responses

What is Base64 Encoding?

Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format. It's designed to carry data stored in binary formats across channels that only reliably support text content. Base64 uses 64 different ASCII characters (A-Z, a-z, 0-9, +, /) to represent binary data.

The encoding process converts groups of three bytes (24 bits) into four Base64 characters. This makes the data approximately 33% larger but ensures it can be safely transmitted through text-based protocols like email, JSON, XML, or URLs without corruption.

How Base64 Encoding Works

Base64 encoding works by taking binary data and dividing it into 6-bit chunks (since 2^6 = 64 possible values). Each 6-bit chunk is then mapped to one of 64 printable ASCII characters. When the input length isn't perfectly divisible by 3, padding characters (=) are added to the end.

For example, the text "Hello" is encoded as "SGVsbG8=" in Base64. Our tool uses JavaScript's built-in btoa() and atob() functions for encoding and decoding, ensuring compatibility and standards compliance.

Common Use Cases

Data URLs: Embed images, fonts, or other files directly in HTML/CSS using Base64-encoded data URLs. This reduces HTTP requests but increases file size.

API Authentication: Basic authentication headers often use Base64 to encode username:password combinations for HTTP requests.

Email Attachments: MIME email protocol uses Base64 to encode binary attachments into text format for transmission.

JSON/XML Data: When binary data needs to be included in JSON or XML documents, Base64 encoding ensures safe transmission.

FAQ

No, Base64 is not encryption. It's a reversible encoding scheme that anyone can decode. Never use Base64 alone to protect sensitive data. Use proper encryption algorithms like AES for security. Base64 is only meant for encoding binary data into text format, not for hiding information.

Standard Base64 uses + and / characters which can cause issues in URLs and filenames. URL-safe Base64 replaces + with - and / with _ to make encoded strings safe for URLs without escaping. Padding (=) may also be omitted in URL-safe encoding.

Base64 encodes 3 bytes (24 bits) into 4 characters (32 bits), creating approximately 33% overhead. Each Base64 character represents 6 bits, so you need 4 characters to represent 3 bytes. This is the trade-off for text-based encoding of binary data.

This tool is designed for text encoding/decoding. For file encoding, you'd need to read the file as binary data first. DevToolsPro.org works with text strings and is perfect for encoding small text snippets, API tokens, or converting Base64 strings back to readable text.

Padding characters (=) are added when the input length isn't divisible by 3. They indicate how many bytes of padding were added to make the encoded string a multiple of 4 characters. One = means 2 bytes were encoded in the last group, two = means 1 byte was encoded.

No, attempting to decode invalid Base64 will result in an error. Valid Base64 strings only contain A-Z, a-z, 0-9, +, / and = characters. If decoding fails, check that your input is properly formatted Base64-encoded data.

Base64 Encoder/Decoder

Base64 Usage Tips

What is Base64 Encoding?

How Base64 Encoding Works

Common Use Cases

FAQ

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