> ## Documentation Index
> Fetch the complete documentation index at: https://iotools.cloud/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Rate limits

> Requests per minute, and how it differs from credits

Rate limits bound how *fast* you call. [Credits](/docs/concepts/credits) bound how *much* you call in a month. They are enforced separately.

## The limits

| Plan        | Requests / minute |
| ----------- | ----------------- |
| Free member | 60                |
| Builder     | 300               |

Per API key, on a fixed 60-second window.

## What counts

Every authenticated request takes a slot, whether or not it runs a tool:

* **REST** — `POST /v1/tool/{slug}`, and the reads too: `GET /v1/tools/list`, `GET /v1/tools/search`, `GET /v1/tool/{slug}`, `GET /v1/me/credits`, `GET /v1/me/usage`. The reads cost no credits, but they do cost a slot.
* **MCP** — every JSON-RPC message you POST to the hosted endpoint, including the `initialize` and `tools/list` a client sends when it connects. A session therefore starts a couple of slots down before your agent calls anything. `search_tools`, `describe_tool`, `get_credits` and `get_usage` count too, even though they cost no credits — so the search → describe → run sequence is three slots, not one.

Only requests we can attribute to your key count, so an unknown slug (`404`) and an unauthenticated request (`401`) do not. Neither does a non-POST request to the MCP endpoint (`405`) — some clients probe it for a stream we don't serve, and that shouldn't cost you anything.

## Hitting one

```json theme={"system"}
{
  "type": "https://iotools.cloud/docs/errors/rate_limited",
  "title": "Rate limited",
  "status": 429,
  "code": "rate_limited",
  "retry_after": 30,
  "request_id": "e4042b29-…"
}
```

The response carries a **`Retry-After` header** as well as `retry_after` in the body. Use it — a fixed backoff either wastes time or hammers the window.

<Note>
  A 429 costs no credits — it is refunded like any other failure.
</Note>

## Concurrent file conversions

File conversions (PDF, Office, background removal) run as background jobs, so they are additionally capped on how many you can have **in flight at once**:

| Plan        | Concurrent conversions |
| ----------- | ---------------------- |
| Signed out  | 1                      |
| Free member | 1                      |
| Ad-free     | 5                      |
| Builder     | 5                      |

Exceeding it returns `too_many_jobs` (429). Credits are unaffected, and a finished or abandoned job frees its slot automatically.

## Being a good client

* **Honour `Retry-After`.** It is the actual remaining window.
* **Retry 429 and 5xx; do not retry 4xx.** A `validation_error` will fail identically forever.
* **Sequential is usually enough.** At 60 req/min, a serial loop with no delay is already near the limit.