Base64 Encoder/Decoder

Base64 is a binary-to-text encoding scheme defined in RFC 4648 used to represent binary data in an ASCII string format. It converts data into a text-only format using 64 safe ASCII characters (A-Z, a-z, 0-9, +, /). It's commonly used to embed images in HTML/CSS, send email attachments, transmit data through JSON APIs, and ensure data integrity in text-based systems.

No. Base64 is an encoding scheme, not an encryption algorithm. It is easily reversible (decoded) by anyone without a key. It provides no security or confidentiality and should never be used to protect sensitive data. Base64 is designed for data integrity and compatibility, not security.

Use Base64 when you need to transmit binary data through text-only channels. Common scenarios include: embedding images as Data URIs in HTML/CSS, encoding email attachments (MIME), sending binary data through JSON/XML APIs, encoding authentication credentials in HTTP headers, storing binary data in text configuration files, and passing complex data through URL parameters.

Base64 works by converting binary data into groups of 6 bits each, then mapping each group to one of 64 printable ASCII characters. Every 3 bytes (24 bits) of input produces 4 characters (24 bits) of Base64 output. If the input length isn't divisible by 3, padding characters (=) are added to complete the final group. This process increases data size by approximately 33%.

The standard btoa() function in browsers only supports ASCII characters. Our tool correctly handles all UTF-8 characters (like emojis 😊 or accents é) by using encodeURIComponent before encoding and decodeURIComponent after decoding, ensuring all international characters, emojis, and special symbols are preserved perfectly.

Absolutely! All encoding and decoding happens entirely in your browser using JavaScript. Your data is never uploaded to our servers, stored anywhere, or transmitted over the internet. Everything is processed locally on your device for complete privacy and security. You can even use this tool offline.

Since all processing happens in your browser, there's no strict server-side limit. The only constraints are your device's memory and browser performance. Our tool can efficiently handle strings with millions of characters. For extremely large files (100MB+), performance may vary depending on your device specifications.

This error occurs when trying to decode text that isn't valid Base64. A valid Base64 string only contains A-Z, a-z, 0-9, +, /, and = (for padding). The string length must be a multiple of 4. Common causes include: extra whitespace, invalid characters, missing padding, or attempting to decode regular text that was never Base64-encoded.

Yes! Our Base64 encoder/decoder is completely free to use for personal, commercial, and enterprise projects without any restrictions. There's no registration required, no usage limits, and no attribution needed.

No, Base64 encoding actually increases data size by approximately 33%. For example, 3 bytes of binary data become 4 bytes of Base64 text. Base64 is not a compression algorithm—it's an encoding scheme designed for data compatibility and integrity, not size reduction. If you need compression, use tools like gzip before Base64 encoding.