If you have ever looked at a hosting plan and seen the word “bandwidth”, and had no idea whether the number next to it was good or bad, this is for you.
What Bandwidth Actually Means
Bandwidth is how much data your website sends to visitors.
Every time someone opens a page on your site, your server sends them things: the text, the images, the fonts, the code that makes it work. All of that has a size. Add up everything you send to everyone over a month, and that is your bandwidth usage.
The easiest way to picture it is a water pipe. Storage is the size of your tank, which is how much you can keep. Bandwidth is how much water flows through the pipe to people who ask for it.
Bandwidth Is Not the Same as Storage
People mix these up constantly, so it is worth being clear.
Storage |
Bandwidth |
|---|---|
How much you can keep on the server |
How much you send out to visitors |
Grows when you add files |
Grows when you get more visitors |
A 10 MB image uses 10 MB once |
That same image uses 10 MB every time someone loads it |
That last row is the important one. Storage is a one-off cost. Bandwidth is charged every single time a visitor loads the file.
A Simple Way to Work Out What You Need
Rough maths, but it works:
Average page size × pages viewed per visit × visitors per month = bandwidth used
So say your pages are about 2 MB each, people look at 3 pages per visit, and you get 5,000 visitors a month. That is 2 × 3 × 5,000 = 30,000 MB, or roughly 30 GB a month.
Now double it. Traffic spikes, bots crawl your site, and things are never as tidy as the maths suggests. So budget around 60 GB.
For most new blogs and small business sites, actual usage is far lower than people expect. A site getting a few thousand visits a month rarely troubles even a modest plan.
What About “Unlimited” Bandwidth?
Lots of hosts advertise unlimited bandwidth. It is not really unlimited.
What they mean is that they will not charge you per gigabyte, and most customers use so little that it does not matter. But buried in the terms there is almost always a fair use policy. Push it hard enough and they will ask you to upgrade or move.
For a normal blog or business site, unlimited is fine and you will never hit the ceiling. If you are hosting video files or big downloads, read the fair use terms properly first.
What Happens If You Run Out
Depends on the host. Usually one of three things:
- They charge you extra for the overage.
- They slow your site down until the month resets.
- They take your site offline until you upgrade.
That last one is the reason to pay attention. Running out on the day a post goes viral is the worst possible timing.
How to Use Less Bandwidth
The good news is that most sites waste an enormous amount, and it is easy to fix.
- Compress your images. This is the big one. Images are usually most of your page weight, and most are far larger than they need to be.
- Use modern image formats. WebP files are much smaller than JPEG or PNG at the same quality.
- Turn on caching. A caching plugin means repeat visitors reload far less.
- Use a CDN. It serves your files from its own servers, so a lot of the traffic never touches your hosting at all.
- Do not host video yourself. Put it on YouTube or Vimeo and embed it. Video eats bandwidth faster than anything else.
Common Questions
Is 10 GB of bandwidth enough?
For a small site with a few thousand visits a month, usually yes. For an image-heavy site or anything with real traffic, it is tight. Do the sum above and see where you land.
Does bandwidth affect my site speed?
Not directly. Bandwidth is a monthly allowance, not a speed limit. But if you go over it, some hosts will throttle you, and then yes, your site gets slower.
Do bots use my bandwidth?
Yes. Search engines crawling your site counts, and so do less welcome bots. It is another reason to leave yourself headroom rather than buying exactly what you calculated.