Base64 Encoder

Key features

• Dedicated Encode and Decode tabs with live conversion roughly 200 ms after you stop typing.
• Fully UTF-8 safe via TextEncoder/TextDecoder — emoji, accented letters and CJK text round-trip intact.
• Decode mode tolerates stray whitespace and line breaks inside the Base64 string.
• Invalid Base64 produces a specific error hint (missing characters, padding or stray symbols) rather than silent garbage.
• Swap to input button pipes the result back as the new input with the mode flipped — perfect for round-trip checking.
• Character counts on both panels plus a one-click Copy of the output.

How it works

1. 1

   Pick a direction

   Stay on the Encode tab to turn text into Base64, or switch to Decode to turn Base64 back into readable text.

2. 2

   Paste into the input

   Type or paste on the left. The result appears on the right almost instantly — no button to press.

3. 3

   Fix errors if pointed out

   If decoding fails, the banner tells you the string isn't valid Base64 — check for missing padding or stray characters. Whitespace is stripped automatically.

4. 4

   Copy or swap

   Copy the output, or press Swap to input to immediately re-process the result in the opposite direction.

Tips for better results

• 💡Base64 output grows about 33% versus the original text — factor that in when sizing payload limits.
• 💡Use the swap button as a sanity check: encode, swap, decode, and confirm you got your original text back.
• 💡Padding '=' at the end is optional when decoding here, but some strict systems require it — keep it when copying between tools.
• 💡Base64-encoded JSON in URLs often also needs URL-encoding; run the result through the URL Encoder for query strings.

Frequently asked questions