Cloud Reliability Comparison
AWS vs Azure vs GCP: Outage Frequency & History Compared
Updated June 2026 · 25 documented major incidents across three clouds
Outage Frequency, In Brief
By documented major incidents, the three hyperscalers cluster around one to two significant outages per year each. Our database records 10 major AWS incidents since 2012, 8 for Azure since 2018, and 7 for GCP since 2016. Raw counts are not a clean reliability ranking - they reflect how long each provider has been tracked and how visible each event was. AWS outages concentrate in us-east-1 and affect the most customers per event; Azure incidents often hit Microsoft 365 and Teams; GCP fails less often but its global control plane lets a single failure scale worldwide within minutes (June 2025). Full side-by-side table, combined timeline, and SLA credit comparison below.
Outage Frequency & History, Side by Side
| Metric | AWS | Azure | GCP |
|---|---|---|---|
| Documented major incidents | 10 | 8 | 7 |
| Tracking window | since 2012 | since 2018 | since 2016 |
| Approx. frequency | ~1-2 / yr | ~1-2 / yr | ~1 / yr |
| Costliest incident | Dec 2021 + S3 Feb 2017, $150M+ each | Oct 2025 Front Door global outage (~8.5h) | Jun 2025 Service Control / IAM (100+ products) |
| Most recent major | May 2026 us-east-1 thermal event (~28h, single AZ) | Oct 2025 Front Door config failure (~8.5h global) | Jun 2025 IAM auth failure (~3h, us-central1 ~7h) |
| SLA credit range | 10% -> 30% (EC2, <99%) | 25% -> 100% (<99%) | 10% -> 50% (Compute, <95%) |
| Failure pattern | Concentrated in us-east-1; affects the most customers per event | Often hits Microsoft 365 and Teams - high enterprise visibility | Rarer, but a global control plane means failures scale worldwide fast |
Incident counts are the major outages documented on each provider page below; they are not exhaustive logs of every status-page event. Providers do not disclose customer-impact figures, so cost figures are aggregate customer-loss estimates from analyst reports and revenue-at-risk modeling (the Oct 2025 figure is CyberCube's preliminary insured-loss range). Updated June 2026.
Combined Outage Timeline (Most Costly, Recent)
| Date | Provider | What Happened | Est. Cost |
|---|---|---|---|
| May 2026 | AWS | us-east-1 (use1-az4) data-center cooling/thermal event; EC2/EBS, ELB, EKS, Redshift, MSK offline ~28h; Coinbase down ~7h | $25M+ est. |
| Nov 2025 | Cloudflare | Config-propagation failure degraded a large share of the web (~2.4B users routed through Cloudflare) | $250M+ est. |
| Oct 2025 | AWS | DynamoDB DNS race condition cascaded to EC2/Lambda/STS; ~70K orgs | $38-581M insured (CyberCube) |
| Oct 2025 | Azure | Front Door data-plane config change failed globally (~8.5h); cascaded to M365, Outlook, Copilot, Azure Portal, Xbox; Alaska Airlines, Costco, Starbucks hit | Not yet quantified |
| Jun 2025 | GCP | Invalid quota policy crashed Service Control; IAM auth failed across 100+ products; cascaded to Cloudflare, Spotify, Discord, OpenAI | $50M+ est. |
| Jul 2024 | CrowdStrike / Azure | Falcon sensor update crashed Windows hosts globally, incl. Azure VMs; airlines, banks, hospitals hit | $5.4B (Fortune 500, Parametrix) |
| Nov 2023 | Azure | Teams, Microsoft 365, and Entra ID outage hit millions of enterprise users (~8h) | $50M+ est. |
| Dec 2021 | AWS | us-east-1 EC2/ECS/Lambda/SNS outage (~7h), major global disruption | $150M+ est. |
| Feb 2017 | AWS | S3 us-east-1 outage (~4h) disrupted a large portion of the internet | $150M+ est. |
Per-provider chronologies: AWS, Azure, GCP. CrowdStrike was a software-update incident, not a cloud-provider failure, but it crashed Windows hosts including Azure VMs - see the CrowdStrike case study.
SLA Credits: What Each Cloud Actually Pays
| Provider (service) | Lower-tier credit | Maximum credit | Claim window |
|---|---|---|---|
| AWS (EC2) | 10% (<99.99%) | 30% (<99%) | 30 days |
| Azure (most services) | 25% (99%-99.99%) | 100% (<99%) | Auto for some since 2024 |
| GCP (Compute Engine) | 10% (99%-99.95%) | 50% (<95%) | 30 days |
All credits are a percentage of the monthly fee for the affected service, applied to future invoices - never your revenue loss. Full SLA credit vs actual loss analysis, or calculate your own exposure.