Fixing 503 "Model overloaded. Please try again in a minute."

A 503 means the model behind the API failed to answer, and the API had already retried before telling you. It is usually brief.

What the error says

HTTP 503
{
  "error": {
    "message": "Model overloaded. Please try again in a minute.",
    "type": "server_error",
    "code": "temporarily_unavailable",
    "param": null
  }
}

On /v1/messages the same case is HTTP 529 overloaded_error, which Anthropic clients treat as retryable.

What already happened before you saw it

When the model answers with a 500, 502, 503, 504, 520 or 529, or a 429 that is not about billing, the API retries quietly: once after about 0.6 seconds and again after about 1.8 seconds. It stops retrying once 60 seconds have passed since your request arrived, or if you cancel. Only if every attempt fails do you get this 503. The hold placed on your balance covers all attempts, and a failed request is not charged.

The response is deliberately generic. Any model failure that is not about context length or images is reported this way, so you get a clean "try again" rather than raw provider text.

How it shows up

SillyTavern shows the message in an error toast; pressing regenerate is the retry. The OpenAI SDKs treat 503 as retryable and by default try twice more with backoff before raising InternalServerError, so in code you may see it only after a few seconds.

Step by step fix

1. Wait a minute and retry.
2. If it persists, try another model from the models list; different models run on different capacity.
3. If a 503 comes back instantly and every time, on every model, check your request body. Unusual parameters the model rejects also land here; strip the request down to model, messages, max_tokens and stream and add options back one by one.
4. For long jobs in code, add your own retry with backoff on 503.

Telling it apart from similar errors

A 502 Upstream request failed. means the connection itself could not be made; see 502. A 429 is covered in 429 Too Many Requests. Context and image problems come back as 400s with their own text, so they are never hidden behind a 503.

FAQ

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