# faster-whisper v1.2.1: what's new, verdict & setup

Canonical: https://theagenticweekly.com/tools/faster-whisper · Released: 2025-10-31 · Last verified: 2026-10-25 · Evidence: Tested (smoke test, 2026-10-25, no language model involved) · Vendor: SYSTRAN · Official site: https://github.com/SYSTRAN/faster-whisper

> Speech-to-text library that runs OpenAI Whisper models with CTranslate2.

## Verdict

**Fast local transcription; on CPU use float32 and check int8 against a reference before trusting it.**

Good for:
- Local, private transcription
- Developers building voice pipelines on CPU

Skip if:
- You need diarisation or a managed service

Tested. Tested 2026-10-25 (America/Chicago). faster-whisper 1.2.1 transcribed 41 s of speech at 2.4 percent word error with the base.en model in float32 (deterministic), but the int8 setting gave 2 to 60 percent on identical audio across runs. Test environment: Linux x86_64 virtual machine (Debian 13), 8 vCPU, 15 GiB RAM, no GPU; no vendor account, login or API key. No language model was involved in this test, so it says nothing about any model, vendor-hosted or local. Not tested: Other audio: one synthetic (Piper) voice, English only, no noise, no accents, no long recordings; GPU, other compute types (float16, int8_float16) and the larger models; Not a benchmark; this is a smoke test on 41 seconds of audio. These are smoke tests, not a benchmark. Full log: /tests/faster-whisper.

Test scope:
- Kind and date: smoke test, 2026-10-25 (America/Chicago). Not a benchmark.
- What we ran: faster-whisper 1.2.1 transcribed 41 s of speech at 2.4 percent word error with the base.en model in float32 (deterministic), but the int8 setting gave 2 to 60 percent on identical audio across runs.
- Model used: None; no language model was involved
- Environment: Linux x86_64 virtual machine (Debian 13), 8 vCPU, 15 GiB RAM, no GPU; no vendor account, login or API key
- Not tested: Other audio: one synthetic (Piper) voice, English only, no noise, no accents, no long recordings; GPU, other compute types (float16, int8_float16) and the larger models; Not a benchmark; this is a smoke test on 41 seconds of audio.

Pricing: Partly verified. Open source; no pricing page read. (checked 2026-10-25)

## Best for

- [Best AI tool for AI voice and speech](https://theagenticweekly.com/best/voice-ai) (#-): MIT-licensed Whisper inference library for CPU and GPU.

## Key facts

faster-whisper reimplements Whisper inference with CTranslate2 for faster CPU and GPU transcription. It is MIT-licensed; v1.2.1 was tagged on 2025-10-31.

- License: MIT (per GitHub)
- Platforms: Python; CPU and NVIDIA GPU
- Pricing model: Open source
- Free tier: Open source, free to use
- Paid plans: Hosted or enterprise offerings not read
- GitHub: SYSTRAN/faster-whisper: 26,138 stars on 2026-10-25, last push 2026-10-25
- Latest release we saw: v1.2.1, 2025-10-31
- How to start: uv pip install faster-whisper av==18.1.0.
- v1.2.1 (2025-10-31): the newest release on the repository when we read it on 2026-10-25.

## How to set it up: Get started with faster-whisper

Install steps are exactly what we ran on 2026-10-25; the test log lists what was and was not covered.

1. **Install and pin av.** In our run an unpinned av release broke first use; pinning fixed it.

```
uv pip install faster-whisper av==18.1.0
```
2. **Transcribe.** Use float32 on CPU if you need repeatable output.

```
WhisperModel("base.en", device="cpu", compute_type="float32")
```

## Pros and cons

Pros:
- MIT license
- Repeatable word error rate in float32 on our test audio

Cons:
- int8 on CPU gave 2.4 to 59.7 percent word error on the same audio run to run in our test
- An unpinned dependency (av 19.0.2) broke first use

## Alternatives

- [Piper](https://theagenticweekly.com/tools/piper): Fast local neural text-to-speech that runs on CPU.
- [Ollama](https://theagenticweekly.com/tools/ollama): The common way to run open models locally on macOS, Windows and Linux, with a cloud option and an MIT-licensed open-source core.
- [llama.cpp](https://theagenticweekly.com/tools/llama-cpp): LLM inference in C/C++: the open-source engine many local-model tools build on; MIT-licensed with near-daily build tags.
- [AssemblyAI](https://theagenticweekly.com/tools/assemblyai): Speech AI APIs for transcription and understanding; start free, pay as you go.
- [Cartesia](https://theagenticweekly.com/tools/cartesia): Realtime voice AI: text-to-speech, speech-to-text in 44 languages and voice agents, with a free plan and credit tiers.
- [Deepgram](https://theagenticweekly.com/tools/deepgram): Voice AI APIs for speech-to-text, text-to-speech and agents with $200 in free credit.
- [Murf AI](https://theagenticweekly.com/tools/murf-ai): Text-to-speech platform with a $10 free API trial, pay-as-you-go credits and per-character API pricing.
- [Resemble AI](https://theagenticweekly.com/tools/resemble-ai): Resemble AI now leads with real-time deepfake detection and watermarking for audio, video and images; plans from free to $1,000 a month.
- [Retell AI](https://theagenticweekly.com/tools/retell): Voice AI agents for phone calls with pay-per-minute pricing and 20 free concurrent calls.
- [Speechify](https://theagenticweekly.com/tools/speechify): Text-to-speech app that reads PDFs, books and web pages aloud, with a Free plan and a $29 monthly premium price.
- [Vapi](https://theagenticweekly.com/tools/vapi): Developer platform for voice agents; $5 free credits, then pay for the minutes you run.

## FAQ

### What is faster-whisper?

A library that runs Whisper speech-to-text models with CTranslate2 for faster inference.

### Is int8 safe on CPU?

Check it first: in our test the same audio gave between 2.4 and 59.7 percent word error across int8 runs, while float32 was stable. See /tests/faster-whisper.

### Why did faster-whisper fail on first use?

An unpinned av 19.0.2 raised a TypeError in our run; av==18.1.0 fixed it.

## What we have not verified

- GPU speed
- Non-English audio, noisy audio, long recordings

## Sources

- [faster-whisper repository (GitHub)](https://github.com/SYSTRAN/faster-whisper) (fetched 2026-10-25)

## How to cite

Agentic Weekly, "faster-whisper v1.2.1: what's new, verdict & setup", last updated 2026-10-25, https://theagenticweekly.com/tools/faster-whisper

Keep the Reported or Tested label when you quote the verdict.
