WebShutter
Read the shutter count and other camera info from a Canon EOS DSLR, straight from the browser over USB.
Notes
- Requires a Chromium-based browser (Chrome / Edge / Opera) — WebUSB is not supported in Firefox or Safari.
- Camera must be in PTP communication mode.
- Supported bodies are the same as the libgphoto2
shuttercounterproperty: 1D C, 1D X, 1D Mk IV, 7D/II, 5D II/III, 6D, 40D–70D, and the xxxD line. Newer bodies (5D IV, 5DS, 80D, 750D/760D, 1300D) don't expose it. - Read-only. This only queries device properties (shutter count, identity, lens, battery, etc.); it changes nothing on the camera.
Protocol log
⚠️ macOS & the PTPCamera problem
On macOS, when you plug in the camera, the system's
PTPCamera helper (used by Image Capture / Photos) grabs the
USB interface. A browser cannot take it away from another process, so
WebUSB will fail to claim the interface until
PTPCamera lets go.
This tool does not try to solve that automatically. Workarounds:
- Quit Image Capture / Photos, then unplug & replug the camera, then click Connect.
- Or disable the auto-grab once (reversible):
defaults -currentHost write com.apple.ImageCapture disableHotPlug -bool true