Base64 Decode
Decode any Base64 string back to text instantly — UTF-8 safe. Free, fast, no sign-up.
That doesn't look like valid Base64 — check for typos.
Decoded text
Step-by-step calculation
| Base64 | Bytes | Text |
|---|
How Base64 decoding works
- Base64 text is split into groups of 4 characters.
- Each group becomes 3 bytes (6 bits per character).
- The bytes are read back as UTF-8 text.
Example: "SGk=" → 48 69 → "Hi".
Frequently asked questions
How do I decode Base64?
Paste the Base64 string above — the decoder handles the rest, including '=' padding.
Why does my Base64 end with '='?
'=' is padding added when the input length isn't a multiple of 3 bytes.
I get an error — why?
Base64 only uses A–Z, a–z, 0–9, +, / and '=' padding. Other characters mean the string is damaged or incomplete.
Need to encode? Try our Base64 encoder.