GRX10 Research · December 2025

LLM speed benchmark: 309 models ranked by latency

We timed 346 large language models from Bengaluru on 12 December 2025 and ranked the 309 that answered by median response time. The fastest answered in 344 ms. The median model took 1.7 seconds, and 96 models took longer than 3 seconds.

Free report · 121 pages · GRX10 Research

Summary

How fast large language models answer.

344 ms
Fastest median response
OpenAI: gpt-oss-safeguard-20b
1.74 s
Median across all models
309 models that answered
76
Models under 1 second
29 of them under 700 ms
96
Models over 3 seconds
slowest: 27.4 s
346
Models tested
37 failed to answer
2
Runs per model
via OpenRouter, network time included
Why it matters

Latency decides whether a voice agent sounds human.

A caller notices a pause of more than a second. In a cascaded voice agent the language model is only one step, after speech-to-text and before text-to-speech, so a model that takes 1.7 seconds to answer makes the whole call feel slow.

GRX10 Voice AI uses a single audio-to-audio model, and its first-word response is under 700 ms on real phone calls. We ran this benchmark to see how far general-purpose language models are from that target.

#ModelMedian latency
1OpenAI: gpt-oss-safeguard-20b344 ms
2Qwen: Qwen-Plus351 ms
3Qwen: Qwen-Turbo429 ms
4Qwen: Qwen VL Plus431 ms
5Qwen: Qwen Plus 0728453 ms
6Mistral: Codestral 2508472 ms
7Qwen: Qwen-Max507 ms
8Mistral Large 2411508 ms
9TheDrummer: Skyfall 36B V2510 ms
10Mistral: Ministral 3 8B 2512554 ms
11Mistral: Ministral 3 3B 2512556 ms
12OpenAI: GPT-4 Turbo Preview578 ms
13Meta: Llama 4 Maverick582 ms
14Google: Gemma 3 4B583 ms
15Cogito V2 Preview Llama 109B593 ms
16Mistral: Pixtral 12B598 ms
17NVIDIA: Llama 3.1 Nemotron Ultra 253B v1607 ms
18Mistral: Ministral 3B618 ms
19Mistral: Ministral 8B618 ms
20Qwen: Qwen VL Max631 ms
Method

How we measured.

Each model received the same short prompt twice through OpenRouter from Bengaluru, India, on 12 December 2025. We recorded the full round-trip time including network latency and ranked models by median. Results change with provider load and region, so treat them as a snapshot.

See also
Voice AI →Conversational AI guide →All resources →