Browser file transfer speeds on the same Wi-Fi: what to expect
On one Wi-Fi network the file, more than the tool, decides how long a transfer takes: on a healthy 5 GHz link a 100 MB file moves in seconds, while a 1 MB file spends most of its life setting up. This page collects what to expect from Lan-Share, LocalSend, and PairDrop by file size, what actually limits the speed, and a four-step method to measure your own network with checksums.
Step by step
Put both devices on the same Wi-Fi
Join a 5 GHz network on both ends, keep them in the same room, and turn off any VPN on either device. Band, distance, and interference move the numbers more than any tool does, so hold them constant — that is what makes two runs comparable.
Generate checksummed test files
Create three files of 1 MB, 10 MB, and 100 MB — any deterministic generator works; the Lan-Share open-source repository ships one (scripts/test-file.mjs). Record each file's SHA-256 checksum before sending, so what arrives can be verified byte for byte.
Pair the two ends and send each size three times
Pair browser-to-browser with the 8-digit code, then send each file three times in a row. Start the stopwatch when the receiving side begins pulling the file and stop it when the last byte lands. Three runs iron out the spikes; keep the middle one.
Verify the bytes and take the median
Hash each received file and compare it with the original before trusting a run — a transfer that quietly re-encoded or truncated the file is a failed run, not a fast one. All three tools send files byte for byte, so a correct run and a fast run are the same run.
Typical results on one healthy 5 GHz network (estimates, not a lab record)
| File size | Typical time | Typical rate |
|---|
| 1 MB | 1–3 s | mostly setup latency |
|---|
| 10 MB | 2–6 s | 10–35 MB/s |
|---|
| 100 MB | 3–10 s | 10–35 MB/s |
|---|
Why one range, not one number per tool
The three tools ride the same Wi-Fi in the same way: the file moves device to device over the local network, chunk by chunk, with no cloud relay in the path. On the same network they land within each other's spread, which is why this table gives one range per file size instead of three — differences between tools on one afternoon are noise next to the difference between networks.
The ranges describe a healthy home network: a recent router on 5 GHz, both devices in the same room, no VPN. Move to 2.4 GHz, add walls, or share the air with three streaming devices, and the same file takes multiples longer — no tool can opt out of the physics.
How to read the numbers
The 1 MB row is mostly latency, not speed: pairing overhead, connection setup, and the last-packet wait dominate a file that small, so treat it as a floor rather than a throughput figure. The 100 MB row is the honest one — by that point a transfer has settled into its steady-state rate.
Speeds are megabytes per second (MB/s), not megabits (Mb/s): divide the router's advertised megabits by eight to compare. A Wi-Fi link that advertises 600 Mb/s carries at most about 75 MB/s, and real transfers land well under that because Wi-Fi is a shared, half-duplex medium where every retransmission costs time.
What slows a transfer down
The 2.4 GHz band is the usual suspect: it carries a fraction of 5 GHz throughput and absorbs interference from every neighbor. Distance matters next — a phone in another room can halve the rate. A VPN on either device drags local traffic through an extra tunnel, and on public or office networks, client isolation can block device-to-device transfers entirely.
Beyond the network, the transfer path itself matters. Lan-Share moves files in 256 KB chunks with an 8 MB in-flight window, which keeps the pipe full without exhausting browser memory; a direct peer-to-peer path shows up in the connection details as Direct. When a tool falls back to relaying through a server, the speed cap becomes that server's bandwidth instead of your Wi-Fi.
Why these are ranges, not a lab record
These numbers are expectations for a typical healthy network, not recorded runs from a test lab — hardware varies too much for one table to promise more. Real measurements shift with the router, the apartment, the phone generation, and the day.
That is what the four-step method above is for: on your own network, with your own checksummed files, you get numbers you can trust in about ten minutes — and the ranges here tell you whether what you measured is normal.
Which one to pick
Since the ranges overlap, decide on friction instead: Lan-Share runs in a browser with no install on either end, LocalSend needs its app on both devices but adds auto-discovery, and PairDrop is also browser-only but depends on a public relay for pairing. The per-tool details live in the LocalSend alternative and PairDrop alternative comparisons.
For a deeper walk-through of the browser-to-browser method itself — including the offline case where no internet exists at all — see the guide to transferring files without internet, and the PC-to-PC guide for the two-computer case.
Troubleshooting
- Transfers run at a small fraction of the speeds on this page
Why it happens The devices are on the 2.4 GHz band, far from the router, or the phone is holding a weak signal behind walls.
How to fix it Move both devices onto the router's 5 GHz SSID and into the same room, then retest. If the router publishes separate band names, pick the 5 GHz one explicitly rather than relying on band steering.
- Speed starts high, then collapses partway through a large file
Why it happens Another device on the network started its own heavy transfer, or the sending phone began thermal throttling.
How to fix it Pause other downloads and streaming on the network, take the phone out of a case or off a wireless charger, and rerun. If the collapse repeats at the same point, test with the router's channel width set to 80 MHz on 5 GHz.
- A VPN is active and the transfer crawls or fails
Why it happens The VPN routes traffic through an external server, so the file leaves your home network and returns, and some VPN clients block local subnet traffic outright.
How to fix it Turn the VPN off on both ends for local transfers. If policy forbids that, check whether the VPN client offers an allow-local-access setting and enable it.
- The two devices never see each other on hotel, office, or campus Wi-Fi
Why it happens Those networks enable client isolation: connected devices cannot address each other, so no direct transfer can start regardless of the tool.
How to fix it Create a phone hotspot and join both devices to it — the hotspot is a private network with no isolation. The hotspot transfer guide covers this end to end.
FAQ
How fast is browser file transfer on the same Wi-Fi?
On a healthy 5 GHz network, count on the ranges in the table above: a few seconds for 10 MB and roughly three to ten seconds for 100 MB, which works out to a steady 10–35 MB/s. The rule of thumb: take the router's advertised megabits, divide by eight, then expect half to two-thirds of that.
Why is the transfer speed lower than my router advertises?
The advertised number is the raw radio link in one direction under ideal conditions. Real transfers share the air with acknowledgements and retransmissions, cross other devices' traffic, and pay protocol overhead on every chunk. Wi-Fi also drops to a lower rate as signal weakens, so distance alone can halve throughput.
Do any of these tools compress files to transfer faster?
No. All three send a file byte for byte — nothing is re-encoded on the way, which is exactly why the checksum method above works. Compression would only help on slow links anyway, and on a local Wi-Fi network the wire is rarely the bottleneck that re-encoding would relieve.
Does file size change the transfer speed?
Yes, at the small end. A 1 MB transfer spends most of its life on setup — pairing, opening the data channel, and waiting for the final packet — so its effective speed looks much worse than the tool's real throughput. From tens of megabytes upward, the rate settles and file size stops mattering.
Is a browser tab really as fast as a native app?
They ride the same WebRTC data channel over the same Wi-Fi, so the link does not care which one you use. The browser adds a memory ceiling, which is why chunked transfer with backpressure matters, but on a home network the Wi-Fi, not the tab, is the cap. Run the four-step method once on each and compare on your own hardware.