Base64 Encoder & Decoder
Encode text to Base64 or decode it back to plain text, instantly and privately. Everything runs in your browser — nothing is uploaded.
What Base64 is and when you need it
Base64 is a way of writing any data — text, an image, a file — using only 64 safe characters (A–Z, a–z, 0–9, + and /). It exists because some systems can only handle plain text reliably: email attachments, JSON payloads, data URLs in CSS, and basic authentication headers all lean on Base64 to carry binary or special-character data through a text-only channel without it getting mangled.
This tool encodes text to Base64 and decodes Base64 back to text, entirely in your browser. Pick a mode, paste your input, and the result appears instantly with a character count. Because it is fully local, you can safely paste tokens or snippets you would not want to send to a server.
Base64 is encoding, not encryption
Anyone can decode Base64. It scrambles nothing and hides nothing — it is fully reversible by design. Never use Base64 to "hide" a password or secret. For real protection you need encryption or a password manager. See our guide on creating strong passwords.
Common uses for Base64
- Data URLs: embedding a small image or font directly inside HTML or CSS as text.
- Email (MIME): attachments are Base64-encoded so binary files survive text-only mail transport.
- APIs and JSON: sending small binary blobs (a thumbnail, a signature) inside a JSON field.
- Basic auth headers: the
username:passwordpair is Base64-encoded (which is exactly why it must travel over HTTPS).
Frequently asked questions
Is Base64 the same as encryption?
No. Base64 is a reversible encoding that anyone can decode in seconds with a tool like this one. It provides no security or secrecy. Use it to transport data safely through text-only systems, not to protect sensitive information.
Why does Base64 make text longer?
Base64 represents every 3 bytes of input as 4 characters of output, so encoded data is about 33% larger than the original. That overhead is the trade-off for being safe to send through text-only channels.
Can I decode any Base64 string here?
You can decode standard Base64 text. If the string is corrupted, truncated or actually binary file data, decoding to readable text may fail or show garbled characters — the tool will flag input that is not valid Base64.
Does this Base64 tool upload my data?
No. Encoding and decoding run entirely in your browser using the built-in btoa and atob functions. Nothing you paste leaves your device, so it is safe for snippets you would not send to a server.
What characters does Base64 use?
Standard Base64 uses the 64 characters A–Z, a–z, 0–9, plus (+) and slash (/), with the equals sign (=) as padding at the end. A URL-safe variant swaps + and / for - and _.
This tool runs entirely in your browser — nothing you type is sent to our servers. Tudug is reader-supported and may earn from ads.