FormatCalc library
File & internet
without the noise.
Convert common workbook and image files locally, or estimate transfer time and bandwidth. Selected files remain in the browser; generated downloads should be checked before the original is removed. Choose a tool below to get started—no account required.
File Size Converter
Convert binary file-size units from bytes through pebibytes.
Download Time Calculator
Estimate how long a download will take across common size and speed units.
Bandwidth Calculator
Estimate monthly transfer from traffic, page views, and page size.
XLSX to CSV
Convert the first worksheet in an Excel workbook into CSV locally.
XLSX to JSON
Convert the first worksheet in an Excel workbook into JSON locally.
CSV to XLSX
Create a downloadable Excel workbook from CSV without uploading it.
JSON to XLSX
Create an Excel workbook from a JSON array of records without uploading it.
Image Format Converter
Convert images to PNG, JPEG, or WebP in your browser.
Image Resizer
Resize an image to exact pixel dimensions locally.
Image Metadata Remover
Strip EXIF and location metadata by safely re-encoding an image locally.