Base64 Encoder & Decoder
Encode text or files to Base64, or decode Base64 back to readable text. Supports URL-safe encoding. All processing happens in your browser — nothing is sent to a server.
Features
Real-time Processing
Output updates instantly as you type — no buttons to click for encode or decode.
URL-safe Mode
Toggle URL-safe Base64 that replaces + and / with - and _ for use in URLs and tokens.
File Encoding
Load any file and convert it to Base64 for embedding in data URIs or transferring.
Copy & Download
One-click copy to clipboard or download the result as a text file.
Swap Direction
Instantly swap input and output to reverse the operation — encode becomes decode and vice versa.
100% Client-side
All processing runs in your browser. No data is ever sent to a server.
About Base64 Encoding
Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format by translating it into a radix-64 representation. It is widely used when there is a need to encode binary data that needs to be stored and transferred over media that is designed to deal with textual data. This ensures that the data remains intact without modification during transport.
Common use cases include embedding images directly in CSS or HTML using data URIs, encoding attachments for email (MIME), transmitting data in URLs or cookies, and implementing HTTP Basic authentication. The URL-safe variant replaces the standard + and / characters with - and _ respectively, making it safe for use in URLs, filenames, and tokens without additional encoding.
Our tool handles all Base64 operations entirely within your browser using native JavaScript APIs. There are no file size limits, no server uploads, and no registration required. Whether you need to encode a short string or a large file, the conversion happens instantly and privately.
Frequently Asked Questions
What is Base64 encoding used for?▼
Base64 encoding is used to convert binary data into a text format that can be safely transmitted over text-based protocols. Common uses include embedding images in CSS/HTML as data URIs, encoding email attachments (MIME), embedding fonts, and transmitting binary data in JSON or XML payloads.
What is URL-safe Base64?▼
URL-safe Base64 replaces the + and / characters with - and _ respectively, and removes padding = characters. This makes the encoded string safe to include in URLs, query parameters, and filenames without additional percent-encoding.
Is my data safe when using this tool?▼
Yes. All encoding and decoding is performed entirely in your browser using JavaScript. Your data is never uploaded to any server or stored anywhere.
Can I encode files larger than text?▼
Yes. Click the 'Load File' button to select any file from your computer. The file will be read and converted to Base64. Note that Base64 increases the size of data by approximately 33%, so very large files may produce large output strings.
Why does the encoded output look longer than the input?▼
Base64 encoding increases data size by about 33% because it represents every 3 bytes of binary data as 4 ASCII characters. This is a normal and expected behavior of the encoding scheme.