Base64 File 変換
「Base64 File 変換」はコード、データと QRに使えるブラウザツールです。入力内容と結果は通常この端末内で処理され、登録は必要ありません。
使い方
使い方
- Choose a file up to 10 MB and review its detected MIME type.
- Select Base64 body or complete data URL, then inspect the generated text.
- Copy the result or download it as a plain text file when you need it elsewhere.
A local file encoder
The browser FileReader API converts the selected file on this device. Hello Keyboard Tools does not upload, store, or inspect the file contents, and the page works without a server request.
MIME, size, and output boundaries
Files up to 10 MB are accepted. The browser-reported MIME type is shown and used for data URLs; files with an empty or generic type can produce application/octet-stream. Base64 adds about one third to the byte size, so large output may be unsuitable for HTML attributes, CSS, headers, or clipboard apps. Binary data is represented as text only; this tool does not decode, preview, or execute it.
よくある質問
あわせて知りたいこと
What is the difference between Base64 and a data URL?
Base64 output contains only the encoded file bytes. A data URL adds a MIME type and prefix, such as data:image/png;base64, before those bytes.
Which file types are supported?
Any local file up to 10 MB can be read. The browser MIME type is displayed when available; no server-side type detection is performed.
Does my file leave my device?
No. Reading, encoding, copying, and downloading happen locally in your browser. Nothing is sent to Hello Keyboard Tools.