Calculate download/upload time based on file size and bandwidth.
Bandwidth 計算機 is a free online audio & video tool that works right in your browser — whatever you enter is processed locally and never sent to a server. No installation, no signup; works on both phone and desktop, ready to use instantly.
We noticed most online tools upload your files to remote servers. Since privacy is our core principle, we built this tool to process everything locally in your browser.
はい、完全無料で登録不要です。
はい、モバイルブラウザでタッチ操作に対応しています。
Audio & Video
Yes. Bandwidth 計算機 is a pure front-end tool: whatever you type or paste is processed only in your browser's memory and never sent to a server. It disappears as soon as you refresh or close the page.
🔒 Privacy & Security：All processing happens locally in your browser. Files are never uploaded or stored.
🔒 Privacy: All processing happens locally in your browser. Your files and data never leave your device — no upload, no server, no tracking.