Broadband upload speed: the number nobody quotes you

Broadband upload speed is the half of your connection nobody sells you on. It is also the half that decides whether a video call holds together. Packages are advertised on the download figure, the one that governs how fast things arrive, and upload governs how fast things leave. On a lot of UK connections it is a small fraction of the number on the advert. Most people never think about it once, right up until the afternoon they are the one freezing on a call while everybody else sounds fine.

What is broadband upload speed?

It is how quickly your connection can send data out to the internet, measured in megabits per second in the same way the download figure is. Download is everything coming in: a page loading, a film streaming, a game patching itself overnight. Upload is everything going out. Your face and voice on a call, a photo syncing to the cloud, a file attached to an email, a backup running while you sleep.

Most of what a household does leans heavily on download, which is why providers lead on that number and why connections are usually built to favour it. Then somebody starts working from home. The balance shifts, and the smaller number stops being a technicality.

Why is the upload number always smaller?

Because of how the line was built, not because a provider is holding something back. On a part-copper connection, where fibre reaches a green street cabinet and copper carries the last stretch to the house, the capacity of that copper pair is split unevenly and most of it goes to download. The upload ceiling ends up well below the advertised download figure. It falls further the further you live from the cabinet, which is why two neighbours on the same package can get very different answers.

Full fibre changes the picture, though not always by as much as people expect. A fibre running the whole way to the property has no copper bottleneck, so upload can be far higher, and some networks sell packages where upload and download match exactly. Others still set upload well below download, which is a choice about the product rather than a limit of the cable. It is worth reading the specification rather than assuming, and our guide to full fibre, FTTC and cable sets out what each of them actually is.

How much do you actually need?

There is no single answer, but there is a floor worth knowing. Government and Ofcom define a decent broadband connection as one capable of at least 10 megabits per second down and 1 megabit per second up, a definition the House of Commons Library briefing on the broadband universal service obligation sets out in full. That single megabit was judged enough for a household to browse, stream and make a video call.

Treat it as a floor rather than a target. It describes one household doing one thing at a time, and it is the level at which a connection stops being considered inadequate, not the level at which it feels comfortable. What pushes a home above it is simultaneous use:

• More than one person on a call at once. Two people in separate meetings is the most common way a household discovers its upload ceiling.
• Sending large files. Video, design work, photography, anything measured in gigabytes rather than megabytes.
• Cloud backup and photo sync. Quiet, constant, and happy to use everything you have unless you tell it not to.
• Cameras and doorbells. A camera uploading continuously is a small load that never stops, which is a different shape of problem from a one-off transfer.
• Streaming or playing to an audience. Broadcasting out is almost entirely an upload job, and it is unforgiving of a connection that wobbles.

If none of that describes your house, a large upload figure is capacity you are paying for and will never use. Our guide to what speed you need goes through the download side of the same question.

The speed guarantee only counts the download

This is the part that catches people out. When you sign up, your provider gives you a minimum guaranteed speed for your particular line, and it appears on the key facts you are sent. Under Ofcom's broadband speeds code of practice, if your speed falls below that figure and the provider cannot put it right within 30 days, you can leave the contract without paying an exit fee.

That guaranteed figure is a download speed. So a connection whose download holds up perfectly while the upload is barely usable has not, on the face of it, fallen below its guarantee, and the exit route most people have heard of is not the one that applies. Upload simply has less protection built around it. That is worth knowing before you ring up expecting the same remedy.

What you have instead is the fault process. If your upload has collapsed against what it used to manage, report it as a fault, measure it repeatedly and at different times of day, and keep the results. Getting a complaint taken seriously covers what to do when the first answer is that everything looks fine at their end.

Is it your line or your wifi?

Before blaming the package, rule out the house. Wifi is shared between every device in range and it degrades with distance, walls and interference, so it throttles upload just as easily as download. A laptop two rooms and a chimney breast away from the router may be nowhere near what the line can actually do.

Test with a cable straight into the router if you can, and test more than once. Evening congestion, a backup you forgot was running and a busy street cabinet all look identical from the sofa. If the wired result is fine and the wireless one is not, the problem is inside your walls, and telling a wifi problem from a line problem works through how to separate the two.

What it is worth paying for

Here is the trade-off, stated plainly. For a household that mostly watches things, paying extra for upload buys capacity that sits idle, and the money is better spent elsewhere. For a household where two people work from home, it is one of the few upgrades that changes the day rather than a benchmark score.

The annoying part is that upload is rarely advertised as prominently as download, so comparing it takes more effort than it should. On the networks we track the upload figure tends to sit in the package detail rather than the headline, and two packages with identical download speeds can be a long way apart on it. Check it first, not last.

What is available to you is decided street by street rather than town by town, so the useful starting point is finding out which networks actually reach your address. Our availability checker is the quickest way to see the list, and from there the upload figure is a question worth asking before you sign anything.

Frequently asked questions

What counts as a good upload speed?

It depends entirely on what leaves your house. One person on a video call with nothing else running needs very little. Two people on separate calls, a phone backing up photos and a camera sending footage to the cloud all at once is a different household, and that is where a low upload ceiling starts to show. If nothing you do sends much out, a big upload figure is capacity you will never touch.

Does upload speed affect video calls?

Yes, and it is usually the cause when you are the one who freezes while everybody else sounds fine. A video call sends your camera and microphone out continuously, so it leans on upload in a way that streaming a film does not. If your picture breaks up at your end only, the upload side of the connection is the first thing to look at rather than the download figure on your bill.

Do full fibre providers give you the same upload as download?

Some do and some do not, and it is a product decision rather than a limit of the technology. A fibre running all the way to the property is physically capable of matching upload to download, and several networks sell packages that do exactly that. Plenty of others set upload well below download on the same fibre. Check the specific package rather than assuming full fibre means symmetrical.

Can I leave my contract if the upload speed is poor?

Not usually on the strength of the speed guarantee, because the minimum guaranteed speed you were given at sign-up is a download figure. If your upload has collapsed compared with what it used to do, the route is to report it as a fault rather than a speed shortfall, and to keep a record of what you measured and when. That is a slower path but it is the one that fits.

Will a better router improve my upload speed?

Only if the router is what is holding it back, which is less common than people hope. A router cannot send data out faster than the line allows. What a better router or a wired connection can fix is congestion and interference inside the house, so it is worth ruling that out before you conclude the line is at fault or pay for a faster package.