Base64 Converter
Choose encode or decode
How to encode and decode Base64
Base64 represents arbitrary bytes using only 64 printable characters (A–Z, a–z, 0–9, + and /) plus = for padding. It exists so that binary data — images, archives, cryptographic keys — can travel through channels that only accept text, such as email bodies, JSON payloads, HTML attributes and configuration files. Base64 is an encoding, not encryption: anyone can decode it, so it never makes data secret.
This tool handles both directions. To encode, paste text into the input box or pick a file, and the Base64 string appears immediately. To decode, paste a Base64 string and the original text is restored. If the string is malformed — a stray line break, a missing = at the end — you get a clear error instead of silently wrong output.
Everything runs in your browser with JavaScript; nothing you paste or upload is sent to a server. That makes it safe for values you would hesitate to paste into a random online converter, such as configuration entries containing API keys or internal documents. No installation and no account are needed, and it works the same on a phone.
Frequently asked questions
- Is Base64 a form of encryption?
- No. Base64 is a reversible encoding that anyone can decode. It should never be used to hide passwords or secrets.
- Can I encode image files?
- Yes. Choose a file and any binary, including images, is converted to a Base64 string — useful for embedding a data URI in CSS or HTML.
- Why do I get "Invalid Base64 string"?
- Usually because line breaks or spaces were copied in, or the trailing = padding is missing. Copy the original string again and retry.
- Is my data uploaded anywhere?
- No. Encoding and decoding happen entirely inside your browser, and no data is sent to any server.
