Reliability isn't an opinion — it's something you can measure. We continuously monitor 12 major LLM API providers — OpenAI (ChatGPT, GPT-4o), Anthropic (Claude Opus, Sonnet, Haiku), Google (Gemini Pro, Gemini Flash), xAI (Grok), DeepSeek, Mistral, Groq, Cohere, Perplexity, Together AI, AWS Bedrock, and Azure OpenAI — and rank them by observed uptime. Below: the live leaderboard, plus head-to-head comparisons for the matchups developers actually search for. The leader changes over time as new incidents accumulate; this page reflects what's true right now.
The matchups people actually search for, with live data. Each card shows real observed uptime, total incidents, and cumulative downtime for both providers since we started tracking them. Click a comparison below to jump directly to it.
Every LLM API on this list — including OpenAI's ChatGPT and GPT-4o, Anthropic's Claude Opus, Sonnet, and Haiku, Google's Gemini Pro and Gemini Flash, xAI's Grok, DeepSeek, Mistral, Groq, Cohere, Perplexity, Together AI, AWS Bedrock, and Azure OpenAI — is probed continuously from Cloudflare's edge network. Each probe records whether the endpoint responded and how long it took. From these probes we derive three numbers that drive the ranking:
Uptime % — total monitored time minus total downtime, divided by total monitored time. This is the column on the right of the table. A score of 99.9% means the provider was unavailable for less than 0.1% of the time we've watched them.
# incidents — how many times the provider transitioned from operational to a degraded or outage state since we began tracking them. An incident ends when the provider returns to operational.
Downtime — the cumulative wall-clock duration of all incidents combined. If a provider had two outages, one for 30 seconds and one for 2 minutes, total downtime is 2m 30s.
Providers we've monitored for fewer than 7 days appear at the bottom of the ranking tagged NEW. They could have a perfect 100% score on paper, but with so little observed history that score isn't yet a meaningful claim. As soon as a new provider crosses the 7-day mark — or experiences its first incident — it joins the main ranking.
Reliability changes over time, so we measure it live. The ranking on this page reflects observed uptime since we started monitoring each provider. Providers with at least 7 days of monitoring history are ranked first; newer providers appear at the bottom until enough data accumulates to judge fairly.
Compare the live uptime of Anthropic's Claude versus OpenAI's ChatGPT in our head-to-head section above. We track every status transition for both providers, so the answer reflects real observed availability rather than marketing claims. The current leader is shown in the verdict line of each comparison card.
Google Gemini and OpenAI GPT-4 are compared head-to-head in the Comparisons section. Both are tracked continuously. Whichever has the higher uptime percentage and fewer total incidents is the current reliability leader — but the relative gap is often small, so check the live numbers before making a decision.
We compare OpenAI (creator of ChatGPT and GPT-4o) against Anthropic (creator of Claude) using identical methodology: continuous probing of each company's public API endpoint. The current reliability leader is shown in the OpenAI vs Anthropic comparison card above with live data.
DeepSeek is one of the newer providers we track. Its current uptime is shown in the rankings table and the head-to-head comparison with OpenAI's ChatGPT. Note that DeepSeek may have less monitoring history than ChatGPT, which is reflected by the NEW tag in the rankings.
For production workloads, look at three things in our data: total uptime percentage (higher is better), total incident count (fewer is better), and the longest active uptime streak (more recent stability is a better signal than ancient history). The Claude vs Gemini comparison card shows all three side by side.
We probe each provider's API endpoint at regular intervals from Cloudflare's edge network. Every probe records availability and latency. From this we compute total downtime, incident counts, and uptime percentage cumulatively since we began monitoring each provider.
Uptime % = (total monitored time − total downtime) / total monitored time × 100. Total downtime includes the elapsed time of any currently-ongoing incident, so the score updates in real time during outages.
Each new incident a provider experiences adds to its total downtime, which lowers its uptime percentage and can change its rank. Providers that go long stretches without incidents climb the rankings as their relative reliability becomes more apparent.
Yes — every monitored provider has its own dedicated page: OpenAI (ChatGPT, GPT-4o), Anthropic (Claude Opus, Sonnet, Haiku), Google Gemini Pro, Groq, Mistral, xAI (Grok), Cohere, Perplexity, Together AI, DeepSeek, AWS Bedrock, and Azure OpenAI.