Upload Speed Test

Upload Speed Test – The Number That Decides Your Calls, Backups and Uploads

Download speed gets all the attention, but upload speed is the one you feel the moment something goes wrong: your face freezes on a work call, a video takes all evening to send, a cloud backup never quite finishes. This upload speed test puts that forgotten number front and centre. Press Start above and, in about twenty seconds, you will know your real upload speed – measured properly, not guessed – alongside your ping, jitter and a quick download reading for context. It is part of Speed Test UK, our free set of UK connection tools.

Most speed tests bury upload at the end of a combined run. Here it is the main event: the test sends generated data from your device to Cloudflare’s edge network over several parallel connections for ten seconds, counts every byte your browser actually sends, and leaves out the opening moments while the connection ramps up. The test data is created on your device and discarded by the server – none of your own files are involved.

As with any browser test, you are measuring this device on this connection right now. A wired laptop tells you what your line can do; a phone on Wi-Fi tells you what your home set-up delivers to the sofa. Both are worth knowing – just judge your provider by the wired one.

How to Run This Upload Speed Test Properly

Upload results are easily sabotaged by things you cannot see, so a fair method matters even more here than for downloads.

• Pause the silent uploaders. Cloud photo backups, Drive/Dropbox/OneDrive syncing, security camera uploads and game updates all send data constantly. Pause them for the test, or your result measures what is left over, not what your line can do.
• Test wired for the verdict. Plug a laptop into your router with an Ethernet cable. Wi-Fi upload is often the first casualty of a weak signal, and a poor Wi-Fi result proves nothing about your line.
• Close video calls and streams. A meeting left open in another tab is uploading your camera the whole time.
• Press Start and let all three stages finish. The test checks ping and jitter, takes a quick download reading, then spends a full ten seconds on upload alone.
• Write the numbers down. Upload, download, ping, jitter, the time, and wired or Wi-Fi. Upload faults are often intermittent, and a log over a few days is what convinces a provider.
• Repeat at a different time. A morning and an evening result show whether your upload collapses when the street gets busy.

For the complete picture in one run, our broadband speed test measures download and upload together with the same care. If your upload is fine but calls still break up, skip ahead to the jitter section below – the culprit is often stability, not speed.

What Your Upload Speed Result Means

Upload speed is measured in Mbps and works in the opposite direction to download: it is how fast data leaves your home. Video calls, sending files, live streaming, cloud backup, uploading videos and online gaming (which constantly sends your position to the server) all depend on it. UK broadband is deliberately asymmetric – packages sell far more download than upload – so upload is nearly always the smaller number, and the first to run out.

A worked example makes it real. A 1 GB video file takes about 2 hours at 1 Mbps, 15 minutes at 10 Mbps, and under 2 minutes at 75 Mbps. If you regularly send video, that difference is your working day. Our what is a good upload speed guide breaks the numbers down by activity, from doorbell cameras to live streaming.

Ping and jitter matter here too

Calls do not just need upload speed; they need it delivered evenly. Jitter – how much your response time wobbles – is what makes voices robotic and pictures smear even when the speed figure looks fine. Under 10 ms of jitter is healthy; regular readings above 30 ms, or any packet loss, will spoil calls on any package. If that is your pattern, run our ping tester and jitter test and read the results together with this one.

Upload Speeds You Should Expect from UK Packages

Upload is where UK package families differ most, and where the glossy headline hides the truth. Part-fibre (FTTC) packages from BT, Sky, TalkTalk, EE and Plusnet typically upload at around 10 Mbps on entry tiers and 17–20 Mbps on the faster 67 Mbps tier – a ceiling set by the copper technology itself. Full fibre on the Openreach network steps up through roughly 30 Mbps (100/150 tiers), 50 Mbps (300), 75 Mbps (500) and 110 Mbps (900). Virgin Media’s cable network downloads quickly but uploads modestly for the price – even Gig1 sits around 100–110 Mbps up, and its mid tiers far less. Some CityFibre-based services offer much stronger, sometimes symmetrical uploads, which is why creators in those areas can do noticeably better.

Your personal benchmark is not the advert, though: it is the estimate and minimum guaranteed speed in your order confirmation. Providers advertising under UK rules quote speeds at least half of customers achieve at peak times, but upload guarantees are usually framed around the download figure, so keep your own test log – it is the clearest evidence of what your line actually does. The UK broadband providers hub links to a dedicated test and guide for each major network.

Why Is My Upload Speed So Slow?

Work through these in order. Upload problems feel mysterious, but the causes are usually mundane.

• Your package is built that way. The most common reason of all. A 67 Mbps part-fibre package with 19 Mbps upload is not faulty; it is the product working as sold. If upload is your bottleneck every day, only a full fibre tier (or a symmetrical service where available) truly fixes it.
• Something is already uploading. A phone backing up a holiday’s worth of photos, a doorbell camera, a cloud drive syncing a big folder – each takes a slice, and on a 10 Mbps upload there are not many slices. Pause them and retest before concluding anything.
• Wi-Fi, again. Upload power from phones and laptops is limited, and a weak signal costs upload speed before download. Test wired; if wired is right, work on router position and coverage with our Wi-Fi speed test guide.
• Peak-time congestion. Evenings strain part-fibre uploads noticeably. A wired result that is healthy at 10am and poor at 8pm, night after night, is a reportable pattern, not bad luck.
• An old router or cable. A failing Ethernet lead or elderly router can cap one direction oddly. Swap the cable, restart the router once, and retest.
• A line fault. Upload that collapses after rain, drops to near zero, or swings wildly between tests points to the line itself – on full fibre, check the optical box for a red LOS light. Faults often hit upload first, which is why this test exists.

How This Test Works – and Its Honest Limits

The test opens four parallel uploads to Cloudflare’s edge network – the same public measurement endpoints behind Cloudflare’s own speed test – and counts bytes using your browser’s upload progress events, which report exactly what the browser has handed to the network. Payloads adapt to your line: small on slow connections so the test does not swamp them, larger on fast ones so the pipe stays full. The final figure excludes roughly the first 1.5 seconds while the uploads ramp up.

Two limits are worth knowing. Browsers count data as it leaves the device, which on a very slow line can briefly run ahead of what the line has truly carried; a ten-second window and the ramp exclusion keep that honest. And like every speed test, this one measures one moment: devices, Wi-Fi and neighbours all leave fingerprints. Repeat the test, wired, at different times – the pattern is the truth.

Below What You Were Promised?

If your upload is persistently far below the level your package delivers to similar lines – or your download is below the minimum guaranteed speed in your order confirmation – you have grounds to raise it. Major UK providers follow Ofcom’s Broadband Speeds Code of Practice for the speeds they guarantee: in general terms, report the problem with evidence, allow the provider a period to fix it (commonly 30 days from when the fault is reported and confirmed), and if speeds still cannot be restored you can normally leave without an early termination charge.

Evidence wins these conversations: three or more wired tests on different days, including an evening, with times noted, plus your guaranteed figure from your order paperwork. For impartial background, see Ofcom’s broadband and Wi-Fi help, and check what your street can realistically get via Openreach and Thinkbroadband before you call.

Upload Speed Test FAQs

What is a good upload speed in the UK?

For a single home worker on video calls, 10 Mbps is workable and 20 Mbps is comfortable. Households with two people on calls, cloud backups running and a streamer in the house should look for 30 Mbps or more. Creators uploading video regularly will feel every step up to 75–110 Mbps on full fibre. On part-fibre, 17–20 Mbps is simply the ceiling – judge your result against your package, not against full fibre numbers.

Why is my upload speed so much lower than my download?

By design. UK residential broadband is asymmetric: networks are built expecting homes to receive far more than they send, so packages allocate most capacity to download. Part-fibre technology hard-codes the imbalance; full fibre narrows it but keeps it. Only some newer full fibre services (mainly on CityFibre) offer equal up and down speeds.

Why do video calls freeze when my download speed is fine?

A call sends as much as it receives. If your upload is nearly full – or jitter is high – your outgoing picture and voice break up first, which is why you can see everyone clearly while they cannot see you. Check your upload result and jitter together; one of them is almost always the culprit.

How accurate is this upload speed test?

Accurate enough to judge your line and support a complaint, if you test fairly: wired, silent uploaders paused, repeated at different times. Browsers count data as it leaves your device over a ten-second window with the ramp-up removed, which keeps fast and slow lines honest. Small run-to-run variation is normal; a persistent gap to your package’s typical upload is not.

Can I improve my upload speed without changing package?

Sometimes: test and work wired where it matters, position your router for a stronger signal, schedule big backups for overnight, and replace tired cables. But if your wired upload already matches your package’s typical figure, the limit is the product itself – the lasting fix is a tier with a stronger upload, usually full fibre.

Does this test upload any of my files?

No. The test generates meaningless data on your device purely to measure how fast it can be sent, and the receiving server discards it. Nothing from your device – no files, photos or documents – is read or transmitted, and no results are stored.

Keep Your Upload Honest: Test, Log, Compare

Upload is the number that quietly decides whether working from home feels easy or exhausting. Run this test again tonight at your busiest moment, set both results beside your package’s typical upload, and you will know whether you are looking at a Wi-Fi fix, a scheduling fix – or a package that has simply run out of road for your household. For the full picture any time, head back to Speed Test UK and run the complete set of checks.