No sign-up, no server round-trip. Every tool below does the work locally with the Canvas, Web Audio and File APIs, so your files never leave your device.
Split a list of names into balanced random groups, or shuffle it. Instant, repeatable with a seed.
Trim whitespace, drop empty rows, de-duplicate lines and normalise headers in a CSV you paste in.
Choose which columns identify a duplicate and whether to keep the first or last matching row.
Add a text watermark to many images at once, straight in the browser.
Cut an audio file to the part you want and download a WAV.
Convert WebP images to PNG in batch.
Convert WebP photos to smaller JPG files with a quality setting you control.
Find the best JPG quality that fits a maximum file-size limit.