V-Rex (Vision Representation & Experimentation) is a free desktop app for the whole loop: annotate pictures with Grounding DINO and SAM,
train small heads on frozen DINOv2/DINOv3 backbones in minutes, run them, and let them annotate new data.
Installs into your Applications folder, without admin rights and without a security warning.
Not in the browser: macOS blocks unsigned apps that a browser downloaded.
Run it again to update. Intel Macs are not supported (PyTorch no longer builds for them).
The installers are small (about 35–45 MB, most of it the moving backgrounds). On its first start the app downloads Python and PyTorch once,
from the official sources, in exactly the versions it was tested with: about 1 GB, or about 3.5 GB with
NVIDIA GPU support. After that it works offline.
Your GPU
NVIDIA cards are detected and used through CUDA, Apple silicon through MPS. Without a GPU the app runs
on the CPU; you can switch later in the app.
Open source
MIT licensed. Models are downloaded in the app from Hugging Face; your pictures and datasets stay on
your computer, or in cloud storage you connect yourself. No telemetry.