Estimate the size of your ZIP archive before zipping. Input file sizes and types to see predicted compression ratios and space savings.
Add files to the estimator to build your virtual archive.
Choose the compression algorithm or standard level.
View the calculated size estimates and compression savings instantly.
Your data is processed entirely inside your browser using client-side JavaScript. Nothing ever travels over a network to any server — making BunchTool the most private option available.
Because everything runs locally in your browser, there are no upload queues or server wait times. Results appear in seconds regardless of your internet speed — or even without any connection at all.
Accurately predict archive size before spending time on actual compression. Ideal for checking email attachment limit boundaries.