Base64 Converter
Instant text encoding and decoding
automatically as you enter text
Base64 - encoding and decoding
🔄 What is Base64 and why is it needed?
Base64 is an encoding standard that turns any binary data (pictures, files, archives) into a secure text string consisting of 64 characters (A-Z, a-z, 0-9, “+” and “/”).
Where is this used?
- Email: For sending attachments (pictures, documents) within the text protocol of the letter.
- Web development: Embedding small icons directly into CSS or HTML (Data URI) so as not to create an extra request to the server.
- API and authorization: Passing login and password in Basic Auth headers.
⚙️ How it works (Technical part)
The algorithm takes every 3 bytes of the original data (24 bits) and divides them into 4 groups of 6 bits. Each group turns into a symbol from a special table.
Example on the word "Man":
ASCII codes: 77, 97, 110
Bits: 01001101 01100001 01101110
-----------------------------------
Breakdown 6 bits: 010011 | 010110 | 000101 | 101110
Numbers (indices): 19, 22, 5, 46
Base64 result: T W F u
Because of this feature, the volume of encoded text is always increased by approximately 33% compared to the original.
❓ Frequently asked questions (FAQ)
🔹 Why do I see “crackers” when decoding?
Most often the problem is in the encoding of the source text. Our tool works with the UTF-8 standard (the modern web standard). If the text was originally in Windows-1251, the result may not be correct. Also make sure you haven't copied any extra spaces.
🔹 How do you know if a string is Base64?
Such a line consists only of Latin letters, numbers, “+” and “/” signs. The length of the string is always a multiple of 4. If there are not enough characters, “=” signs (one or two) are added at the end. For example: Hello=.
🔹 Is there a limit on text length?
Technically no, but the browser may freeze when processing text that is several megabytes in size. If you are working with huge strings, we recommend that you first check their size using our character counting tool.
🔹 Is it safe?
Absolutely. The entire process happens inside your browser using JavaScript. Your data is not sent to the server, so no one but you will see it.