What is Uptime in Web Hosting?

posted by Farhan on December 1, 2019

Uptime is the average time that a server has stayed up and run. This is usually listed as a percentage like “99.9 % uptime.” Uptime is a fantastic measure of how good a web hosting company is at keeping their servers up and running. If a hosting service has a high percentage of uptime, which means their servers stay up and running, so any website you host with them should stay up and running as well. Since web pages are unable to keep customers down, uptime is very important.

Problems With Grading a Web Host on Uptime

The biggest problem with ranking a host on their uptime is that you usually don’t have a way to check there independently. If the host says that they have uptime of 99.9 percent, you will take them at their word. But it’s more to it. Uptime is known as a percentage of time almost. But a percentage of what amount of time? If JoeBlos Web Hosting has a 99% uptime, that means they have a 1% downtime. Over the course of a week, their server would be down for 1 hour, 40 minutes, and 48 seconds. This would mean your server would be down as much as 87.36 hours per year or more than 3 days on average over a year. Three days doesn’t sound like all that much until you’re not making any sales from the website and are receiving calls from the VP (or worse yet, the CEO). And normally the frantic calls start after 3 hours, not 3 days.

Uptime percentages are misleading. 99% uptime sounds great, but it could mean a 3-day outage every year. Here are some mathematical explanations of uptimes:

  • Uptime 98% = 28.8 minutes a day or 3.4 hours a week or 14.4 hours a month or 7.3 days a year
  • Uptime 99% = 14.4 minutes a day or 1.7 hours a week or 7.2 hours a month or 3.65 days a year
  • Uptime 99.5% = 7.2 minutes a day or 0.84 hours a week or 3.6 hours a month or 1.83 days a year
  • Uptime 99.9% = 1.44 minutes a day or 0.17 hours a week or 0.72 hours a month or 8.8 hours a year

Another way to think about uptime is in how much it will cost you when the server does go down. And all servers go down periodically. If your web page brings $1000 a month, a 98 percent uptime host could reduce your profits by $20 a month or as much as $240 a year. And that’s only in sales lost. If your customers or search engines begin to think that your page is unstable, they will stop coming back and start dropping $1000 a month.

Looking at their uptime guarantees when selecting your web hosting provider we suggest only going with a company that offers 99.5 percent or higher guaranteed uptime. Some offer guaranteed uptime of at least 99 percent.

Uptime Guarantees Can Be Misleading Too

Uptime guarantees are not usually what you might think they are. If your hosting agreement varies significantly from any other hosting agreement that we have ever seen, the uptime guarantee works like this:

We guarantee that if your website goes down for more than 3.6 hours per month in unscheduled outages, we will refund the cost of the hosting for the amount of time you reported and your website was checked to be down.

Let’s break that down:

How long was the downtime? – We already know that 3.6 hours per month is 99% uptime. So any amount of time that your site is down below that amount of time is within the 1% outage rate that they guarantee. In other words, if your site goes down for 3.5 hours in a month, that’s too bad.

Unscheduled outages – Your hosting service may call it something else, but what this means is that if they let you know that they are going to be performing an upgrade the server next weekend and the website will be down for 72 hours, this is not protected by the uptime guarantee.. Most hosts don’t take their sites down for more than 4 hours at a time, but problems can happen, and depending upon your hosting agreement, even longer than anticipated maintenance outages will not kick in the uptime guarantee.

Refunding the cost of hosting – this is the important part. If your website earns $1000 a month in sales and is down for 4 hours, you’ve lost $5.56. Most hosting packages cost around $10-20 per month. So they will refund you between 6 and 12 cents.

You reporting the outage – Many uptime guarantees only refund you your money if you report the outage. And then they only refund you for the amount of time that you noticed your site was down. This is fine if you have monitoring systems to let you know the minute your site goes down and comes back up again. But most of us don’t, so you won’t be reimbursed for the full outage if you don’t know how long it really was.

Other Uptime Issues


Uptime is a reflection of how long the machine that is running your website stays up and running. But that machine can be up and working and your website down. If you aren’t maintaining the web server software (and other software like PHP and databases) for your site, you should make sure that your hosting agreement includes guarantees for the run time software as well as the uptime of the hardware.


If you did something to your website that broke it, that will almost never be covered by an uptime guarantee.


If you’ve defined that your website went down because of no fault of your own, and it was the hardware crashing instead of software, it can be challenging to get your reimbursement. Most hosting providers have a lot of hoops they want you to jump through to claim the reimbursement. They are probably hoping that you will decide that the amount of effort involved is not worth the 12 cents you’ll receive.

Uptime Is Still Important

Don’t be mistaken, having a hosting provider that guarantees uptime is much better than one that doesn’t. But don’t believe that your website will never go down if a provider guarantees 99 % uptime. What is more likely is that you will be reimbursed for the expense of the hosting during the downtime if your site goes down.

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