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Slow transfer? Five checks.

A local transfer doesn’t go through the internet: its speed depends on the Wi-Fi between your two devices. What matters most, in order: the band (5 GHz rather than 2.4 GHz), distance and walls, a phone sharing its hotspot while still on another Wi-Fi, a busy router, then the devices themselves. In the best conditions, GreySpace sends up to 1 GB in 9 seconds. And the fastest setup is often the simplest: the hotspot of a recent phone, on 5 GHz, with a single device connected.

Reviewed on 27 September 2026 by Fabien Chauveau, who makes GreySpace. These tips apply to other local transfer apps too.

Check them in order.

After each change, send the same file again and compare the average speed. GreySpace shows it at the end of every transfer.

  1. The Wi-Fi band: 5 GHz rather than 2.4 GHz

    This is the most common cause. 2.4 GHz reaches further and goes through walls better, but it is much slower. 5 GHz, and the 6 GHz band of Wi-Fi 6E devices, are much faster at short range. Many routers broadcast two networks, one with “5G” or “5GHz” in its name: pick that one on both devices. To see which band you’re on:

    • Windows PC: Settings, Network & internet, Wi-Fi, your network’s properties, the “Network band” line.
    • Mac: hold the Option key and click the Wi-Fi icon in the menu bar. The channel and band show under your network.
    • Android hotspot: the band is set in the hotspot settings (below).

  2. Distance and walls

    5 GHz loses strength quickly with distance and doesn’t go through walls well. Bring both devices close to the router, or to the phone sharing its hotspot. In the same room, with no wall between them, is where the speed is best.

  3. A hotspot phone that stays on another Wi-Fi

    Many Android phones can share a hotspot while staying connected to a Wi-Fi (home router, train, hotel). Their radio then serves two networks at once, and the hotspot follows that Wi-Fi’s channel: the transfer slows down, and it can drop when the phone switches access points. Turn off the Wi-Fi of the phone that shares: the hotspot stays on, and it only has your transfer to serve.

  4. A busy router, or an old one

    Everything going through the router at the same time slows your transfer: a streamed movie, a cloud backup, a console downloading. An old router also tops out lower than a recent phone. In both cases, a recent phone’s hotspot can be faster than the router.

  5. The devices themselves

    The transfer goes at the speed of the slower of the two: an older computer or phone, with a Wi-Fi 4 or Wi-Fi 5 chip, won’t keep up with a Wi-Fi 6 device. During the transfer, plug the devices in if you can, turn off power saving mode and your VPN, and pause syncing (iCloud Photos, OneDrive, Google Drive): it takes its share of the Wi-Fi. On iPhone, keep GreySpace open, on screen.

The fastest setup.

A recent phone’s hotspot, just for your transfer. It works with no internet at all, too.

  1. On the phone that shares, turn off Wi-Fi

    On Android, turn off the phone’s Wi-Fi, then turn on the hotspot: it now only serves your network. On iPhone, Apple asks for Cellular Data to stay on for Personal Hotspot; your transfer itself doesn’t go through it.

  2. Pick the 5 GHz band

    • Samsung Galaxy: Settings, Connections, Mobile Hotspot and Tethering, Mobile Hotspot, then the band: 5 GHz rather than 2.4 GHz. Names and options vary by model.
    • Other Android phones: in the Wi-Fi hotspot settings, look for “Band” or “Frequency”.
    • iPhone: in Settings, Personal Hotspot, leave “Maximize Compatibility” off. When on, it limits the hotspot to 2.4 GHz. Only turn it on if an older computer can’t see the network.

  3. One device connected, right next to it

    Connect only the computer (or the other phone) to the hotspot, and put the two devices side by side. Every extra device connected takes its share of the bandwidth.

  4. Send, and compare

    Start the transfer in GreySpace, with the app open on both sides. At the end, the app shows the time and the average speed: compare them with the ones before.

People often ask

For anything else, email us.

What speed should I expect?

In the best conditions (Wi-Fi 6 or a 5 GHz hotspot, recent devices close together), GreySpace sends up to 1 GB in 9 seconds. On a Wi-Fi 5 router, expect around 1 GB in 20 seconds. On 2.4 GHz, it’s several times slower. GreySpace never throttles the speed, even on Free.

My internet connection is slow. Does it matter?

No. The transfer goes straight from one device to the other over Wi-Fi, without going through the internet: fast fiber doesn’t speed it up, a slow connection doesn’t slow it down. It even works with no internet at all.

Why is a folder of photos slower than a video of the same size?

Each file takes a little work on top of the transfer itself: opening it, announcing it to the other device, checking it and saving it on arrival. On a 1 GB video, that work barely counts. On 300 photos, it happens 300 times.

The speed goes up and down during the transfer. Is that normal?

Yes. Wi-Fi shares the airwaves with nearby networks, and the speed varies with what’s going on around you, especially on 2.4 GHz and in crowded places (apartment buildings, stations, trains). Judge by the average speed shown at the end, not by a single moment.

See also

Didn’t find your answer? Write to [email protected] or drop by Discord with your two devices, your network (home router, office, hotspot) and the message GreySpace shows.

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