AI Model Popularity Index
Updated July 1, 2026

Which AI models are the most popular in May 2026?

Monthly rankings of the most-used AI language models, commercial and open source. Data sourced from HuggingFace, web reports, and real-time research. Updated automatically every month.

As of May 2026, OpenAI's GPT-4o remains the most widely used commercial model with over 400M users, while newer releases like GPT-5.5 and Claude Opus 4.8 are rapidly gaining traction. The market is split between high-performance closed models and cost-effective open-source alternatives like DeepSeek V4-Pro, with multimodal capabilities becoming a key differentiator.

Commercial models

Usage estimates based on public reports and web research (Perplexity).

1
GPT-4oOpenAI Stable

ChatGPT reached 400M weekly active users in early 2026 (OpenAI blog, Feb 2026)

400M+

2
GPT-5.5OpenAI Rising

GPT-5.5 Instant became the new default in ChatGPT on May 5, 2026 (OpenAI, May 5 2026)

150M+

3
Claude Opus 4.8Anthropic Rising

Claude Opus 4.8 topped the Artificial Analysis Intelligence Index in mid-2026 (Anthropic blog, May 28 2026)

120M+

4
Claude Sonnet 4.6Anthropic Stable

Claude Sonnet 4.6 is the balanced everyday workhorse for real users (Anthropic review, May 2026)

90M+

5
Gemini 3.1 ProGoogle Rising

Gemini 3.1 Pro leads on multimodal tasks with 94.3% GPQA Diamond score (Google AI, May 2026)

110M+

6
Gemini 3.5 FlashGoogle Stable

Gemini 3.5 Flash is optimized for fast, high-volume everyday tasks (Google AI blog, May 2026)

80M+

7
DeepSeek V4-ProDeepSeek Rising

DeepSeek V4-Pro is the strongest open-weight model at $0.27/M input tokens (DeepSeek API, April 24 2026)

50M+

8
Grok-4xAI Rising

Grok-4 ranks among the top generalists in 2026 alongside GPT-5.2 (Zapier report, May 2026)

40M+

9
Qwen 3.6 Max-PreviewAlibaba Rising

Qwen 3.6 Max-Preview tops six coding benchmarks simultaneously (Alibaba Cloud, May 2026)

35M+

Open source models

Ranked by total downloads on HuggingFace, a strong proxy for developer and researcher adoption.

Sources

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