API Limits | Speechify API

Character limits

Endpoint	Limit	Use case
`/v1/audio/speech`	2,000 characters	Short-form text (sentences, paragraphs)
`/v1/audio/stream`	20,000 characters	Long-form text (articles, chapters)

Character counts include SSML tags. For text longer than the limit, split it into multiple requests.

Rate limits

Plan	Requests per second
Free	1
Paid	20

Concurrency limits

Plan	Simultaneous requests
Free	1
Paid	15

Both rate and concurrency limits apply per account, not per API key.

Handling 429 responses

When you exceed rate or concurrency limits, the API returns 429 Too Many Requests with a Retry-After header.

Python

TypeScript

1 import time
2 from speechify import Speechify
3 
4 client = Speechify()
5 
6 def generate_with_retry(text, max_retries=3):
7     for attempt in range(max_retries):
8         try:
9             return client.tts.audio.speech(
10                 input=text,
11                 voice_id="george",
12                 audio_format="mp3",
13             )
14         except Exception as e:
15             if "429" in str(e) and attempt < max_retries - 1:
16                 time.sleep(2 ** attempt)
17             else:
18                 raise

Processing long texts

For texts exceeding 20,000 characters, split into chunks and process sequentially:

1 def split_text(text, max_chars=19000):
2     """Split text at sentence boundaries within the character limit."""
3     chunks = []
4     current = ""
5     for sentence in text.split(". "):
6         if len(current) + len(sentence) + 2 > max_chars:
7             chunks.append(current.strip())
8             current = sentence + ". "
9         else:
10             current += sentence + ". "
11     if current.strip():
12         chunks.append(current.strip())
13     return chunks

FAQ

What happens if I exceed the character limit?

The request is rejected with an error response. Split your text into smaller chunks within the allowed limits.

How do I get higher limits?

Upgrade to a paid plan for 20 req/sec and 15 concurrent requests. Enterprise customers can request custom limits — contact sales.

How can I monitor my usage?

Track usage through the Speechify Console dashboard.