Plan a transfer
File transfer time calculator
Estimate upload or download time from a file size and connection speed, with decimal and binary size units plus adjustable transfer efficiency.
Useful browser utilities
Simple tools for working with files
Estimate, convert, generate, or verify with four focused utilities. Open the tool you need—no account is required to use these pages.
All tools
Choose a tool
Clear inputs, exact units, and practical explanations.
Open calculator
Convert units
File size converter
Convert values across bits, bytes, SI decimal units such as MB and GB, and IEC binary units such as MiB and GiB.
Create a password
Secure password generator
Create a random password locally with the browser Web Crypto API. Choose its length and which character classes to include.
Check file integrity
SHA-256 file checksum calculator
Calculate a file’s SHA-256 checksum locally, then compare the 64-character result with an expected checksum.
Built for the task at hand
Focused tools, with the details in view
Each tool explains its units, assumptions, and limits on the page. The password generator and checksum calculator perform their core processing locally in your browser.
File sharing when you need it
Ready to upload or share a file?
Filekub provides browser-based file storage and sharing alongside these utilities.