Pixtamer

Pixtamer is a native Mac app that turns batches of images into web-ready assets. Drop in a folder, pick a format, and export JPEG, PNG, WebP or AVIF with real before/after sizes for every file.

- Resize to fixed sizes or several responsive widths in one pass, with no upscaling

- Rename files in bulk with clean, web-safe names

- Save reusable presets for the jobs you repeat

- Safe exports: originals are never overwritten, and name clashes are handled for you

- Reads JPEG, PNG, HEIC, WebP, AVIF, TIFF, GIF, BMP and JPEG XL

Everything runs on your Mac. No account, no upload, no network access. Free and open source under the MIT licence, signed and notarized by Apple.