What it does

Drag a folder of mixed files in. Coldmill sorts them by what they actually are — by reading the file, not trusting its extension — and offers one target format per group.

Three quality buttons

Small, Balanced, High. No codec pickers, no CRF, no bitrate — unless you open Advanced and ask for them.

Everything at once

One job per processor core, each with live progress and its own cancel.

Size before you start

An estimate per file and for the whole batch, refined against the real byte count while it encodes.

Trim, split, re-frame

Cut a clip on its own filmstrip, split it into pieces, mute it, or change its shape with a crop, bars or a blurred backdrop.

Colour adjustments

Brightness, contrast, saturation and hue, on photographs and video alike.

3D models

stl, obj, glb and gltf built in. Quality reduces the mesh, and the row says how many triangles will survive.

Optional modules

Documents, extra image formats, transcription, text from pictures and read-aloud. Downloaded only if you tick them.

Sixteen languages

Picked up from the system on first run. Right-to-left layouts are laid out properly, not mirrored.

It never phones home

There is no upload step, because there is no server. No account, no telemetry, no analytics, no update ping beyond the one that checks for a new version — and that one only asks GitHub for a version number. Pull the network cable out and everything on this page still works.

The whole thing is open source under the GPL, so that claim is checkable rather than promised.