Transfer is slow or stalls partway
Photo Transfer App typically saturates your WiFi's local speed — meaning a fast home network transfers gigabytes in seconds. If yours is slower than that or stalling, the bottleneck is almost always somewhere in the network path.
1. Check WiFi signal on both devices
Weak WiFi on either end caps the transfer speed. Move both devices closer to the router for a test transfer — if speed jumps, signal was the issue.
2. Are both devices on the same WiFi band?
Most routers broadcast two bands: 2.4 GHz (slow, longer range) and 5 GHz (fast, shorter range). If one device is on 5 GHz and the other on 2.4 GHz, your transfer speed is capped to the slower one.
Where possible, put both devices on 5 GHz for the transfer. On most routers this is the same network name with band-steering enabled, so the device usually picks automatically — but you can force-pick on iOS / Android in WiFi settings.
3. Other heavy network usage
If someone in the house is streaming 4K or downloading a large file at the same time, transfers are throttled. Pause those and retry.
4. iCloud download happening?
If your iPhone uses iCloud Photos with Optimize Storage, the first part of a transfer can feel slow because iOS is fetching full originals from iCloud before sending. See iCloud Photos — does Photo Transfer use the originals?
5. Battery saver mode
Battery saver / Low Power Mode on Android and iOS can throttle background networking. If either device is in low-power mode, take it out for the transfer.
6. Try one fewer file at a time
If a large transfer stalls partway, try sending in smaller batches (e.g. 50 files at a time instead of 500). Splitting the work makes intermittent network blips less likely to interrupt the whole batch.
7. Power-cycle the router
Old standby — if everything else looks fine and transfers still stall, unplug your router for 30 seconds and plug it back in. Routers gradually accumulate state issues over weeks of uptime that a restart cleans up.