AI API Status & Outage Guide for Developers
A practical guide to understanding AI API outages, distinguishing rate limits from true downtime, diagnosing common API error codes, and checking the status of OpenAI, Anthropic, Google Gemini, and other AI APIs.
AI API Status — Current Monitored Providers
Understanding the Difference: API Outage vs. Web App Outage
One of the most common sources of confusion for developers using AI APIs is the distinction between an API outage and a web application outage. These two failure modes look very different and require different responses.
🔌 API Outage
- HTTP 500, 503 responses from API endpoints
- Affects your application and all API users
- The consumer chat interface may still work
- Resolves when the provider restores API infrastructure
- May affect specific model endpoints, not all endpoints
🌐 Web App Outage
- chat.openai.com or claude.ai fails to load
- Affects consumer users, may not affect API
- Frontend routing or CDN issue — backend may be fine
- Your API integration may still work during this
- Resolves when frontend infrastructure is restored
This separation is important: if ChatGPT’s web interface is down, the OpenAI API may still be responding normally. Test your API integration directly rather than assuming that a web app outage also affects the API, and vice versa.
Common AI API Error Codes and What They Mean
429 — Too Many Requests
Rate limit exceeded. You’ve sent too many requests in a given time window. Not a downtime — implement exponential backoff and respect the Retry-After header.
500 — Internal Server Error
The API server encountered an unexpected error. Usually transient — retry with exponential backoff. If persistent, check for an ongoing incident.
503 — Service Unavailable
The server cannot handle requests right now — overloaded or down for maintenance. Retry after a delay. This is the primary indicator of a real outage.
401 — Unauthorized
Your API key is invalid, expired, or missing from the request. Check your Authorization header format and verify your key in the provider dashboard.
402 — Payment Required
Billing issue with your account. Check that your payment method is valid and your account has available credits or an active paid plan.
400 — Bad Request
Your request is malformed — check the request body, parameter names, model ID, and required fields. This is a client-side error, not a server outage.
Rate Limits vs. True Downtime — How to Tell the Difference
Rate limiting is the most commonly mistaken-for-downtime scenario. Here is how to reliably distinguish between a rate limit and a true API outage:
- 1Check the HTTP status code — 429 is a rate limit; 503 is service unavailable. These require different responses.
- 2Read the response body — rate limit responses include details about your current usage and limits; outage responses are typically generic or empty.
- 3Check the Retry-After header — rate limit responses often include this header specifying when you can retry. Downtime responses typically do not include it.
- 4Try with a different API key — if the error follows your key but not another key, it’s account-specific (rate limit or billing). If it affects all keys, it’s likely a genuine service issue.
- 5Check your provider’s usage dashboard — if your usage shows you near your RPM (requests per minute) or TPM (tokens per minute) limit, that’s your rate limit — not an outage.
Best Practices for Handling AI API Downtime in Production
Production applications that depend on AI APIs need resilience strategies to handle both rate limits and true downtime gracefully. Building for failure is not pessimism — it is engineering reality when working with external AI services.
- 1Implement exponential backoff with jitter — on 429 or 503 responses, wait and retry with increasing delays. Add random jitter to avoid synchronized retry storms from multiple clients.
- 2Use a circuit breaker pattern — if multiple consecutive requests fail, stop sending requests temporarily and serve a degraded response. Resume after a cool-down period.
- 3Implement a fallback model — if your primary AI provider is down, have a secondary provider configured. For example, fall back from GPT-4o to Claude if OpenAI is degraded, or vice versa.
- 4Queue time-insensitive requests — for non-real-time tasks like batch content generation, queue requests and process them when the API recovers rather than failing immediately.
- 5Set appropriate request timeouts — AI API response times vary widely. Set generous timeouts (30-120 seconds for complex requests) but do not set them to infinity — hanging requests tie up resources.
- 6Monitor your API error rates — alert on unusual 5xx error rates from your AI provider. A sudden spike in 503s is an early indicator of an emerging outage.
Authentication Errors vs. Service Issues
Authentication failures (HTTP 401 Unauthorized) are frequently confused with service outages, particularly when an API key suddenly stops working after previously working correctly. Common causes include:
Deleted or Rotated Key
The API key was deleted or rotated in the provider dashboard. Generate a new key and update your application configuration.
Billing Failure
Payment method expired or declined, causing the account to be suspended. Update your billing information in the provider dashboard.
Incorrect Header Format
API key not passed correctly — must be “Bearer sk-…” in the Authorization header. Check the exact format required by each provider.
IP Allow List Restriction
Your account has IP restrictions configured. The request is coming from an IP not on the allow list — update the allow list in your account settings.
What to Do During an AI API Outage
When you have confirmed a genuine AI API outage (not rate limits, not auth issues), the recommended approach is:
1. Stop sending requests. Continuing to hammer a degraded API endpoint consumes your rate limit quota and contributes to the load on a recovering system. Implement a circuit breaker to stop requests immediately when an outage is detected.
2. Switch to a fallback provider if critical. If your application cannot tolerate downtime, switch to a secondary AI provider. Design your AI integration layer to be provider-agnostic where possible, with model selection as a configuration parameter.
3. Queue non-real-time work. Store requests that don’t need immediate processing in a queue (SQS, Redis, etc.) and process them once the outage resolves.
4. Monitor and alert your team. If your product depends on an AI API, integrate the monitoring of that API into your alerting infrastructure. An AI API going down should trigger the same kind of alerts as your own service going down.
❓ AI API Status — Frequently Asked Questions
To check OpenAI API status, look at the HTTP response codes your application is receiving. If you are seeing 503 errors without having exceeded your rate limits, check the AI Down Status ChatGPT / OpenAI page for reported incidents. You can also make a simple test API call from a clean environment (e.g., a curl command with your API key) to isolate whether the issue is your application code or the API itself.
Yes. The Claude API is Anthropic’s API, accessed at api.anthropic.com. The Claude API provides access to Claude models including Claude 3 Opus, Claude 3.5 Sonnet, and Claude 3 Haiku. When the Claude AI service is experiencing issues, both the claude.ai web interface and the Anthropic API may be affected, though they can also experience independent incidents.
This is a common scenario with several potential causes: your production API key may have different rate limits or permissions than your test key; your production requests may have higher token counts that trigger different rate limits; your production server may be behind a firewall or NAT that the AI provider’s infrastructure blocks; or your production environment may have different timeout settings that cause longer requests to fail. Test specifically in your production environment’s network configuration to reproduce issues accurately.
Enterprise tiers of major AI API providers typically include SLAs. OpenAI’s enterprise offerings include uptime commitments, and Anthropic offers enterprise agreements that include availability guarantees. Consumer and standard paid API tiers generally do not include formal SLAs — developers should design their applications to tolerate the natural variability in AI API availability rather than relying on guaranteed uptime commitments.
RPM (Requests Per Minute) limits the total number of API calls you can make in a minute. TPM (Tokens Per Minute) limits the total number of tokens — both input and output — processed per minute. You can hit either limit independently: a few long requests can exhaust your TPM while barely touching your RPM, or many short requests can hit your RPM while using minimal TPM. Check both limits in your provider dashboard to identify which you are hitting.
🔗 Related Resources
