Base64エンコード/デコード
Base64文字列を即座にエンコード・デコード。UTF-8テキストとファイルのエンコードに対応。
関連キーワード
How to Use Base64 Encoder/Decoder
Base64 is an encoding scheme that converts binary data into a text string using 64 ASCII characters, commonly used to transmit binary data (like images or files) over text-based protocols such as email (MIME) or JSON APIs. Our Base64 Encoder/Decoder supports both directions: encoding text or binary files to Base64, and decoding Base64 strings back to readable text. UTF-8 text is fully supported, so non-ASCII characters (including Chinese, Japanese, Arabic, and emoji) are correctly encoded and decoded. You can also encode an entire file to Base64 — useful for embedding images directly in HTML or CSS using data URIs.
- 1
Select Encode or Decode mode
Click 'Encode' to convert text or a file to Base64, or 'Decode' to convert a Base64 string back to text.
- 2
Enter your content
Type or paste text to encode/decode, or enable 'File to Base64' mode and select a file.
- 3
Get the result
Click the action button to see the encoded or decoded output, then copy it with one click.
Frequently Asked Questions
Does Base64 encoding encrypt my data?
No. Base64 is an encoding scheme, not encryption. Anyone can decode a Base64 string without a key. Do not use it to protect sensitive information.
Why does the encoded string end with '=' signs?
The '=' characters are padding added to make the Base64 string length a multiple of 4, which is required by the Base64 specification.
How much larger does Base64 make a file?
Base64 encoding increases the data size by approximately 33%, because it uses 4 characters to represent every 3 bytes of binary data.