Question 1

How do I decode a Base64 string online?

Accepted Answer

Paste your Base64 string into the text box above, select 'Decode' as the mode, then click Run. The decoded text appears instantly — no account required.

Question 2

What is Base64 and why is it used?

Accepted Answer

Base64 is an encoding scheme that converts binary data (or any bytes) into a string of 64 printable ASCII characters. It is commonly used to embed images in HTML/CSS, transmit data in JSON APIs, encode email attachments (MIME), and store binary data in text-only formats.

Question 3

What is the difference between standard Base64 and URL-safe Base64?

Accepted Answer

Standard Base64 uses '+' and '/' characters, which have special meanings in URLs. URL-safe Base64 replaces '+' with '-' and '/' with '_', making the output safe to include in URLs and filenames without percent-encoding.

Question 4

Why does my decoded output contain strange characters?

Accepted Answer

Base64 can encode any binary data, not just text. If the original data was binary (an image, a compiled file, etc.), decoding it as UTF-8 text will produce garbled output. Use this tool to check whether the result looks like valid text. If not, the original was binary data rather than a plain-text string.

Base64 Encoder / Decoder

How it works

What you get

Frequently asked questions

Related tools