Uptime SLA Checker
& UK Host Reliability Comparison
Check what your host's uptime guarantee actually means in real downtime. Compare SLAs across 21 UK hosting providers and find the most reliable option for your budget.
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Why Your Host's Uptime SLA Matters More Than You Think
Every hosting provider advertises an uptime guarantee — usually 99.9% or higher. But what does that actually mean for your website? A 99.9% SLA sounds impressive until you realise it allows nearly 9 hours of downtime per year. For an online shop doing £500/hour in sales, that’s £4,500 in potential lost revenue.
Worse, most SLAs are buried in fine print that excludes planned maintenance, network-only coverage, and force majeure events. The compensation for breaches is typically a tiny account credit — not the refund you might expect.
This tool helps you decode your current SLA, understand exactly how much downtime it allows, compare it against every UK hosting provider we review, and make an informed choice about whether upgrading to a higher-tier guarantee is worth it for your specific needs.
Check Your Host's Uptime SLA
Enter your current hosting provider's uptime guarantee percentage to see how it stacks up — and what the promised downtime really means.
Uptime SLA Comparison — UK Hosting Providers
Complete Uptime SLA Comparison Table
All 21 UK hosting providers ranked by uptime guarantee
| # | Provider | Uptime SLA | Grade | Max Down/Month | Max Down/Year | TTFB | Score | From/mo | Visit |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Liquid Web | 100% | S Ultimate | 0 min | 0 min | 136ms | 8.5/10 | £15.01 | Visit |
| 2 | DreamHost | 100% | S Ultimate | 0 min | 0 min | 198ms | 8/10 | £2.05 | Visit |
| 3 | SiteGround | 99.99% | A+ Excellent | ~4 min | ~53 min | 142ms | 9.1/10 | £2.36 | Visit |
| 4 | Cloudways | 99.99% | A+ Excellent | ~4 min | ~53 min | 180ms | 8.5/10 | £8.69 | Visit |
| 5 | IONOS | 99.99% | A+ Excellent | ~4 min | ~53 min | 168ms | 8/10 | £0.79 | Visit |
| 6 | InMotion Hosting | 99.99% | A+ Excellent | ~4 min | ~53 min | 245ms | 7.9/10 | £2.36 | Visit |
| 7 | Fasthosts | 99.99% | A+ Excellent | ~4 min | ~53 min | 145ms | 7.8/10 | £3.95 | Visit |
| 8 | Pressidium | 99.95% | A Very Good | ~22 min | ~4h 23m | 100ms | 9/10 | £13.26 | Visit |
| 9 | WPX | 99.95% | A Very Good | ~22 min | ~4h 23m | 94ms | 8.8/10 | £9.35 | Visit |
| 10 | Kinsta | 99.9% | B+ Industry Standard | ~43 min | ~8h 46m | 98ms | 9.3/10 | £23.70 | Visit |
| 11 | HostArmada | 99.9% | B+ Industry Standard | ~43 min | ~8h 46m | 178ms | 8.5/10 | £1.26 | Visit |
| 12 | Hosting.com | 99.9% | B+ Industry Standard | ~43 min | ~8h 46m | 156ms | 8.2/10 | £2.36 | Visit |
| 13 | HawkHost | 99.9% | B+ Industry Standard | ~43 min | ~8h 46m | 285ms | 8.2/10 | £1.56 | Visit |
| 14 | AccuWeb Hosting | 99.9% | B+ Industry Standard | ~43 min | ~8h 46m | 320ms | 8/10 | £1.24 | Visit |
| 15 | Bluehost | 99.9% | B+ Industry Standard | ~43 min | ~8h 46m | 245ms | 7.8/10 | £2.33 | Visit |
SLA Tier Breakdown
Ultimate & Excellent (100% – 99.99%)
Maximum ~4.3 min downtime/month. Premium-grade reliability for mission-critical sites.
Very Good & Industry Standard (99.95% – 99.9%)
Up to ~43 min downtime/month. Suitable for most businesses and personal projects.
Below Standard & No SLA
No formal guarantee or below 99.9%. Higher risk for business-critical websites.
What Each Uptime Percentage Really Means
The difference between “nines” looks small but translates to significantly different downtime allowances.
| Uptime % | Downtime / Month | Downtime / Year | Grade | UK Hosts at This Tier |
|---|---|---|---|---|
| 100% | 0 min | 0 min | S Ultimate | DreamHost, Liquid Web |
| 99.99% | ~4 min | ~53 min | A+ Excellent | SiteGround, IONOS, InMotion Hosting, Fasthosts, Cloudways |
| 99.95% | ~22 min | ~4h 23m | A Very Good | Pressidium, WPX |
| 99.9% | ~43 min | ~8h 46m | B+ Industry Standard | Bluehost, Kinsta, Hosting.com, HostPapa, HostArmada, HawkHost, AccuWeb Hosting, Flashcloud, Web Hosting Buzz, 123 Reg, EuroDNS |
The “Nines” of Uptime — Explained Simply
In hosting, reliability is measured in “nines” — the number of 9s after the decimal point. Each additional nine represents a 10x improvement in uptime.
Unacceptable for any business website. You'd experience roughly one major outage per month.
The industry baseline. Acceptable for personal sites and small businesses with modest traffic.
A meaningful step up. Good for growing businesses and sites where uptime directly impacts revenue.
Premium-grade reliability. Essential for e-commerce, SaaS, and any site where every minute counts.
6 Things Your Uptime SLA Doesn't Tell You
An SLA is a promise with caveats. Here’s what the fine print typically hides.
Network-Only Guarantee
Many SLAs only cover network connectivity, not server hardware failures, software crashes, or your website's own errors. Your site could be down but the SLA technically unbroken.
Planned Maintenance Excluded
Scheduled maintenance windows (often 2–4 hours monthly) are excluded from uptime calculations. Your site is down, but it doesn't count against their SLA.
Credit-Only Compensation
Most hosts offer account credit (5–25% of monthly fee), not actual refunds. If your £5/mo hosting goes down for 8 hours, you might get £0.25 credit.
Claim Window Restrictions
You typically must file an SLA claim within 7–30 days of the incident, with proof. Many outages go unclaimed because customers don't notice or miss the window.
Measurement Method Matters
Hosts measure uptime differently — some use internal monitoring, others only count total outages. Brief interruptions or slow responses may not register as "downtime."
DDoS & Force Majeure
DDoS attacks, natural disasters, and third-party failures are typically excluded. The biggest risks to your uptime are often not covered by the SLA.
Who Actually Needs Premium Uptime?
Not every website needs 99.99% uptime. Here’s how to match the SLA tier to your actual risk level.
E-commerce Stores
Every minute offline costs sales. A 99.9% SLA allows ~43 min/month of downtime — that could be hundreds in lost revenue during peak hours.
SaaS & Web Apps
If customers rely on your app daily, downtime erodes trust fast. You need 99.99% or better, plus robust incident communication.
Lead-Gen Websites
A contact form that doesn't load means leads you'll never know about. Even brief outages during business hours can cost opportunities.
Content & Blog Sites
Google notices repeated downtime and may lower rankings. For ad-supported sites, downtime directly reduces impression revenue.
Portfolio & Personal Sites
Occasional downtime won't break the bank, but if a potential employer or client visits during an outage, first impressions matter.
Development & Staging
Uptime is less critical for non-public environments. A 99.9% SLA is perfectly adequate — save budget for your production server.
6 Steps to Maximise Your Website's Uptime
Choose a Host with a Strong SLA
Start with a provider that offers at least 99.95% uptime — not just as marketing, but with documented compensation for breaches. Check our comparison table above.
Set Up External Uptime Monitoring
Don't rely on your host's own monitoring. Use UptimeRobot (free), Better Uptime, or Pingdom to independently track your site's availability every 1–5 minutes.
Use a CDN for Redundancy
A CDN like Cloudflare (free tier available) serves cached content from edge servers worldwide. If your origin server goes down briefly, the CDN can still serve cached pages.
Keep Software Updated
Outdated WordPress, plugins, or PHP versions are common crash causes. Enable auto-updates where safe, and test major updates on staging first.
Enable Automated Backups
While backups don't prevent downtime, they slash recovery time from hours to minutes. Ensure daily off-server backups are part of your hosting plan.
Consider Managed Hosting for Mission-Critical Sites
Managed hosts (Kinsta, SiteGround, Cloudways) handle server-level security, updates, and scaling — reducing the chance of downtime from misconfigurations.
Uptime SLA Grade Reference
| Grade | Uptime % | Down/Year | Best For | Example Hosts |
|---|---|---|---|---|
| S Ultimate | 100% | 0 min | Mission-critical apps | DreamHost, Liquid Web |
| A+ Excellent | 99.99% | ~52 min | E-commerce, SaaS | SiteGround, IONOS, Fasthosts, Cloudways |
| A Very Good | 99.95% | ~4h 23m | Growing businesses | Pressidium, WPX |
| B+ Standard | 99.9% | ~8h 46m | Personal, small biz | Bluehost, HostArmada, 123 Reg, Namecheap |
| N/A No SLA | — | Unknown | Dev/testing only | Contabo |
Uptime SLA — Frequently Asked Questions
What is an uptime SLA?
What's the difference between 99.9% and 99.99% uptime?
Does 100% uptime really exist?
What happens if a host breaks their uptime SLA?
How is uptime calculated?
Should I trust the uptime percentage a host advertises?
What's a good uptime SLA for a small business website?
How do I monitor my hosting uptime?
Does shared hosting have worse uptime than VPS?
Which UK hosting providers have the best uptime SLA?
Related Guides
Find the Most Reliable UK Host
Compare uptime guarantees, real performance data, and pricing across all 21 UK hosting providers we review.
Uptime SLA data verified against official provider terms as of April 2026. Prices shown in GBP (converted at ~0.79 for USD-priced hosts). We may earn commissions from qualifying purchases.