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Concurrency
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When you submit audio files to the /v2/transcript endpoint, AssemblyAI processes them concurrently up to your account's concurrency limit. The concurrency limit is the maximum number of transcription jobs that can be actively processing at the same time.
Default limits
| Account type | Concurrent transcriptions |
|---|---|
| Free | 5 |
| Paid | 200+ |
Our services are infinitely scalable and we offer custom concurrency limits that scale to support any workload at no additional cost. If you need a higher concurrency limit, please either contact our Sales team or send an email to support@assemblyai.com.
What happens when you hit the limit
If you submit a transcription that would exceed your concurrency limit, it is added to a queue. Queued transcriptions are processed automatically in FIFO (first-in, first-out) order as previously submitted transcriptions complete.
If you exceed your concurrency limit, you will receive an email stating that your transcripts have been throttled. You will only receive this email once per day.
!Email notifying user that their transcripts have been throttled due to exceeding the Concurrency limit
If your account balance goes below zero, your concurrency limit will be reduced to 1.
HTTP rate limits
In addition to the concurrency limit, there is a rate limit for the API that restricts accounts to a maximum of 20,000 requests per five minutes.
Check your limit
You can view your current concurrency limit on the Rate Limits page of your dashboard.
With the current version of multi-project support, rate limiting is applied at the account level, not at the project level. This means that the rate limits for each API key mirror the rate limits for the account.
For example, if an account has a concurrency limit of 200, each API key for that account will be able to process up to 200 requests concurrently.