What Is an Uptime Guarantee?

Category: Hosting Basics · Updated 2026-10-30

An uptime guarantee is a hosting provider's contractual promise that your site will stay reachable for a stated share of time, often expressed as a service level agreement (SLA) with a target such as 99.9% per month. If the provider misses that target, most plans issue a partial account credit rather than a cash refund, and the promise usually excludes scheduled maintenance and outages outside the provider's control.

What the guarantee actually promises

A hosting SLA states a target percentage, such as 99.9% or 99.99%, and the period it is measured over, almost always a calendar month. The percentage converts into an allowed amount of downtime: at 99.9%, roughly 43 minutes a month; at 99.99%, roughly 4 minutes. The provider tracks this with its own monitoring, so the figure that matters in a dispute is usually the host's measurement, not a third-party monitor you ran yourself.

What usually does not count as downtime

Almost every SLA carves out exceptions. Reading them before you sign up avoids a surprise later.

Common exclusion	Why it is excluded
Scheduled maintenance	Announced in advance, usually with a notice window
DNS or domain registrar issues	Outside the hosting server itself
Your own code, plugin or configuration errors	Not a hosting infrastructure failure
Third-party services (CDN, email provider, payment gateway)	Not operated by the host
Force majeure (natural disasters, major internet outages)	Beyond the provider's control

How SLA credits work

When the guarantee is missed, the usual remedy is a service credit applied to a future invoice, typically a percentage of that month's hosting fee that scales with how far below the target the actual uptime fell. Credits are rarely automatic: most hosts require you to open a support ticket within a set number of days, often 30, and reference the outage dates. Keep your own notes of start and end times, since the claim window can close quickly.

A guarantee is a promise, not insurance

An uptime guarantee is a contract term, not protection against the cost of lost sales, lost leads or reputational damage during an outage. It also cannot make a server more reliable than its design; a well-built platform with good monitoring will beat its stated guarantee in practice, while a struggling one may miss its own target repeatedly and only ever pay out small credits. Before relying on a number, check the provider's public status page for its real incident history over the past several months.

Frequently asked questions

What does a 99.9% uptime guarantee mean?

It means the provider targets no more than about 43 minutes of downtime per 30-day month. A stricter guarantee of 99.99% allows only about 4 minutes a month.

What is an SLA in web hosting?

SLA stands for service level agreement, a contract term that states the uptime percentage a host promises and what happens, usually a service credit, when it is not met.

Do I get money back if my site goes down?

Usually not in cash. Most hosts credit a portion of your account balance toward a future bill rather than issuing a refund, and you typically have to request it within a set time window.

What is excluded from an uptime guarantee?

Scheduled maintenance announced in advance, problems with DNS or third-party services, and downtime caused by your own code or configuration are commonly excluded from the uptime calculation.

How do I claim an SLA credit?

Open a support ticket with the exact dates and times your site was unreachable, as soon as possible after the outage, since most providers set a short deadline for claims.

Is 100% uptime possible?

No hosting provider can honestly promise 100% uptime over the long run, since hardware, networks and software all need occasional maintenance or can fail. A high, consistently met guarantee such as 99.9% is a realistic target for a well-run host.