Web hosting guide
What is uptime in web hosting, and what does 99.9% mean?
Updated on ยท 8 questions answered
Uptime is the share of time a website is reachable, written as a percentage. An uptime of 99.9% means the site can be unreachable for about 8 hours and 46 minutes in a year. The rest of that year it answers visitors.
How much downtime does each uptime figure allow?
99.9% allows about 43 minutes of downtime in a 30-day month. Each extra nine cuts the allowed downtime by ten.
| Uptime | Downtime allowed in a year | Downtime allowed in a 30-day month |
|---|---|---|
| 99% | 3 days 16 hours | 7 hours 12 minutes |
| 99.9% | 8 hours 46 minutes | 43 minutes |
| 99.95% | 4 hours 23 minutes | 22 minutes |
| 99.99% | 53 minutes | 4 minutes |
The table is our own sum: the hours in a 365-day year or a 30-day month, times the share that is not uptime, rounded to the minute.
What is an uptime guarantee?
An uptime guarantee is a promise in the hosting company's terms. If the measured uptime in a month falls below the stated figure, the company gives you something back. It is a refund rule, not a promise that the site will never be down. The wider subject is described in the Wikipedia article on high availability.
What do I get if the guarantee is missed?
A credit on a future bill, in most terms. The credit is a share of one month's fee. It does not cover sales you lost while the site was down. You have to ask for it, within the time the terms give.
What does an uptime guarantee leave out?
Read the terms for these exclusions:
- Planned maintenance that was announced in advance.
- Downtime caused by your own code, plugins or settings.
- Attacks on the site and events outside the company's network.
- Time the account was suspended, for example for an unpaid bill.
How do I measure the uptime of my own site?
- Sign up with an uptime monitoring service.
- Add the address of your home page as a monitor.
- Set the check to run every 1 to 5 minutes.
- Add an email or phone alert for the moment the site stops answering.
- Read the monthly report and compare it with the figure in the plan's terms.
Is 99.9% uptime enough?
Yes, for a blog or a small business site. 43 minutes in a month is rarely noticed. A store that takes orders at every hour should look at the exclusions in the terms as closely as at the percentage.
Does a refund period help if the uptime is poor?
Yes, in the first weeks. Within the refund period you can leave and get the hosting fee back. The guide on the hosting money back guarantee explains what that refund covers.
Which plans did we test?
The Hostinger coupon code page lists the plans we tested at the real checkout and the discount on each period.