Fastest LLM API: Lowest Latency AI Models

Latency kills user experience. We benchmarked every major LLM on speed metrics that matter for production apps. Test them all through LLMWise.

Test all models free

Evaluation criteria

Time to first tokenTokens per secondConsistency under loadStreaming qualityCold start time

Claude Haiku 4.5Anthropic

The fastest production-quality LLM available. Claude Haiku 4.5 delivers sub-200ms time to first token and sustains high throughput under load, making it the top choice for latency-sensitive applications.

Sub-200ms time to first tokenHighest sustained tokens-per-second rateConsistent performance under heavy load

Gemini 3 FlashGoogle

Extremely fast with the added benefit of multimodal input. Gemini 3 Flash is nearly as fast as Haiku while supporting image and video inputs, making it the speed leader for multimodal applications.

Near-instant response for text queriesFastest multimodal processing availableExcellent streaming quality with smooth token delivery

Grok 3xAI

Surprisingly fast with real-time knowledge access. Grok 3 delivers low-latency responses while incorporating current information, a combination no other model matches at this speed tier.

Low latency despite real-time knowledge accessSmooth streaming with consistent token deliveryVision capability without significant speed penalty

GPT-5.2OpenAI

Fast for a frontier model, with the best infrastructure behind it. GPT-5.2 benefits from OpenAI's massive serving infrastructure, delivering reliable latency even during peak usage periods.

Most reliable latency during peak trafficGlobal edge deployment reduces geographic latencyFunction calling adds minimal overhead

Mistral LargeMistral

Efficient architecture keeps latency competitive. Mistral Large punches above its weight on speed thanks to an efficient architecture, and EU hosting means lower latency for European users.

Low latency from EU-based infrastructureEfficient architecture minimizes compute timeGood speed-to-quality ratio for European users

Our recommendation

Claude Haiku 4.5 is the fastest LLM API for pure speed in text tasks. If you need multimodal speed, Gemini 3 Flash is the best option. For applications that need both speed and real-time knowledge, Grok 3 offers a unique combination. Use LLMWise to benchmark actual latency from your infrastructure.

Use LLMWise Compare mode to verify these rankings on your own prompts.

Common questions

Which LLM has the lowest time to first token?

Claude Haiku 4.5 consistently delivers the lowest time to first token, typically under 200 milliseconds. Gemini 3 Flash is a close second. Both are significantly faster than frontier models like GPT-5.2 and Claude Sonnet 4.5.

How can I measure LLM latency for my use case?

LLMWise Compare mode streams responses from multiple models simultaneously, showing real-time latency metrics including time to first token and tokens per second. This gives you accurate latency data from your actual geographic location and network conditions.

Does streaming reduce perceived latency?

Yes, significantly. All models on LLMWise support Server-Sent Events streaming, which lets users see the first tokens within milliseconds even if the full response takes seconds. This dramatically improves perceived responsiveness in chat interfaces.

Try it yourself

500 free credits. One API key. Nine models. No credit card required.

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