Quick Take

OpenAI’s GPT-5.5 Instant and Xiaomi’s MiMo-V2.5 were both released in the spring of 2026. While they share a similar launch window, the two models differ significantly in the amount of information provided to the public. MiMo-V2.5 provides a comprehensive look at its capabilities, whereas GPT-5.5 Instant remains largely opaque regarding its performance indices.

Benchmark Read

MiMo-V2.5 provides a robust dataset for evaluation. It holds an Intelligence index of 49 and a Coding index of 42.1. Its performance across specific benchmarks is as follows:

• GPQA: 0.849
• HLE: 0.252
• SciCode: 0.431
• IFBench: 0.671
• LCR: 0.627
• TerminalBench Hard: 0.417
• TAU2: 0.906

In contrast, GPT-5.5 Instant has no benchmark rows available, and its Intelligence, Coding, and Math indices are currently unknown.

Cost and Speed

Pricing structures reveal a stark contrast between the two models. MiMo-V2.5 is significantly more affordable, with a blended cost of $0.72/1M tokens (Input $0.36/1M, Output $1.80/1M). GPT-5.5 Instant is priced at a premium, with a blended cost of $11.25/1M tokens (Input $5.00/1M, Output $30.00/1M).

Regarding speed, MiMo-V2.5 delivers an output speed of 90.461 tokens per second with a time-to-first-token of 2.459 seconds. Performance metrics for GPT-5.5 Instant remain unknown.

Best Fit

MiMo-V2.5 is best suited for developers and enterprises that require high-performance, cost-effective models with verifiable benchmark data. GPT-5.5 Instant is positioned as a premium offering, likely intended for users who prefer OpenAI’s specific infrastructure and ecosystem, despite the current lack of comparative performance data.