What Is Base64 Encoding and Why Do Developers Use It Everywhere

You have probably seen strings like this in code, APIs, or data URLs: SGVsbG8gV29ybGQ= That is "Hello World" encoded in Base64. If you have worked with images in CSS, email attachments, API tokens, or JSON payloads, you have already used Base64 — maybe without realising it. Here is what Base64 actually is, why it exists, and when you should (and should not) use it. What Is Base64? Base64 is a way to represent binary data using only text characters. It converts any data — text, images, PDFs, anything — into a string made up of 64 characters: A-Z, a-z, 0-9, +, and /. The = sign is used for padding at the end. Every 3 bytes of input become 4 characters of output. That is why Base64 encoded data is always about 33% larger than the original. Why Does Base64 Exist? Many systems were designed to handle text, not raw binary data. Email (SMTP), JSON, XML, HTML, URLs — they all expect printable text characters. If you try to embed a raw image file inside a JSON string, it breaks. Binary data con