Base64 エンコーダ / デコーダ
標準形式と URL-safe 形式の両方で Base64 文字列をエンコード / デコードし、長さやパディング情報も併せて表示します。
AK
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Choose Action
Encode, decode or view information
View Results
See output and extra details
Input (Binary)
101010 111100 110101 ...
Split into 6-bit
101010 111100 110101 ...
Convert to Index
42 60 53 ...
Base64 Characters
q 8 1 ...
100% Private & Secure
All processing happens in your browser. No data is sent to any server.
For file payloads, use Image to Base64 or recover an inline asset with Base64 to Image.
Encode arbitrary UTF-8 text into the standard Base64 alphabet (A-Z, a-z, 0-9, +, /) so it can travel through ASCII-only channels such as email headers, JSON fields, and configuration files. The encoder runs entirely in your browser; no input is uploaded.
The encoded payload uses standard Base64 by default. The output is roughly 4/3 the byte length of the input because every three bytes pack into four characters, with = added for padding when needed.
No. Base64 is a reversible representation, not encryption. Anyone with the encoded string can recover the original bytes.
Base64 inflates payload size by roughly 4/3 because three bytes are packed into four characters and = padding may be added.
No. All encoding is performed locally in this tab — nothing is uploaded to any server.
Browser memory is the only limit. Files up to about 50 MB encode comfortably; larger inputs may slow the browser.