GPT-5.5 Instant
GPT-5.5 Instant (OpenAI) was released on May 5, 2026. In the Epoch AI capability ranking (ECI), it ranks #111 out of 267 models, with 142.45. On Arena, which measures human preference in blind comparisons, it has 1,456 ELO points (#117). Against models of the same generation, its best result is on SciCode: 52.5%, #19 of 54.
Where GPT-5.5 Instant stands out and where it falls behind, by the numbers
GPT-5.5 Instant has published results on 6 tests compiled by Epoch AI. The yardstick here is its generation: its position among the models released between Aug 8, 2025 and Aug 3, 2026 that took the same test. Against the whole archive, which includes 2023 models, a recent release lands near the top of almost everything, and that says nothing.
Where it stands out
Tests where it sits in the top third of its own generation.
Where it falls behind
Tests where it sits in the bottom half of its own generation.
See all 6 tests, one by one
| Test | Score | In its generation | Overall | Test record |
|---|---|---|---|---|
| GPQA Diamond | 82.5% | #56 / 67 | #77 / 173 | 96.4% Gemini 4 Argon |
| AIME 2024 and 2025 (OTIS) | 68.1% | #64 / 67 | #100 / 168 | 100.0% GPT-5.5 |
| CritPt | 0.0% | #54 / 58 (tied with 4) | #91 / 112 | 32.3% GPT-5.6 Sol |
| SciCode | 52.5% | #19 / 54 | #39 / 104 | 66.9% Claude Opus 5.5 |
| Frontiermath Tiers 1 3 V2 | 26.3% | #43 / 50 | #68 / 86 | 93.7% GPT-6 Astra |
| Frontiermath Tier 4 V2 | 2.4% | #36 / 39 (tied with 2) | #60 / 67 | 100.0% GPT-6.1 Sol |
For each test, the model's best effort level counts, as in the ranking. Source of the scores: Epoch AI, under CC BY 4.0.
What to compare GPT-5.5 Instant with
The models from other labs closest in capability and released in the same period, at most two per lab. Click any of them to see its page.
| Model | Lab | ECI | ELO | LiveBench | Release |
|---|---|---|---|---|---|
| Gemini 2.5 Flash (Sep 2025) | Google DeepMind | 143.00 | 1,450 | n/a | Sep 25, 2025 |
| Gemma 4 31B IT | Google DeepMind | 142.86 | n/a | n/a | Apr 2, 2026 |
| Qwen3.5-35B-A3B | Alibaba | 142.48 | 1,457 | n/a | Feb 24, 2026 |
| Qwen3-Max-Instruct | Alibaba | 142.46 | n/a | n/a | Sep 24, 2025 |
| GPT-5.5 Instant | OpenAI | 142.45 | 1,456 | n/a | May 5, 2026 |
| Claude Haiku 4.5 | Anthropic | 142.40 | 1,454 | n/a | Oct 15, 2025 |
| Mistral Medium 3.5 | Mistral AI | 141.47 | 1,461 | n/a | Apr 28, 2026 |
Other models from OpenAI
The models from the same lab closest in time, newest first.
| Model | Release | ECI | ELO | LiveBench | Access |
|---|---|---|---|---|---|
| GPT-5.6 Sol | Jul 9, 2026 | 161.73 | 1,527 | 81.1 | API access |
| GPT-5.6 Terra | Jul 9, 2026 | 159.43 | 1,515 | 77.9 | API access |
| GPT-5.5 Instant | May 5, 2026 | 142.45 | 1,456 | n/a | API access |
| GPT-5.5 Pro | Apr 23, 2026 | 161.97 | n/a | n/a | API access |
| GPT-5.5 | Apr 23, 2026 | 158.95 | 1,533 | 80.2 | API access |
| GPT-5.4 Mini | Mar 17, 2026 | 148.77 | 1,446 | 66.4 | API access |
| GPT-5.4 Nano | Mar 17, 2026 | 146.12 | 1,404 | 69.6 | API access |
| GPT-5.4 Pro | Mar 5, 2026 | 159.00 | n/a | n/a | API access |
| GPT-5.4 | Mar 5, 2026 | 156.72 | 1,519 | 78.0 | API access |
Have you used GPT-5.5 Instant? Rate it
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What people ask about GPT-5.5 Instant
Where does GPT-5.5 Instant rank among AI models?
In the ROO3 AI Benchmark, ordered by the Epoch AI ECI, GPT-5.5 Instant ranks #111 out of 267 models, with an ECI of 142.45. The ECI is a composite index that combines several hard benchmarks into a single scale. The position changes when a new model comes out, and the page is refreshed six times a day.
What is GPT-5.5 Instant best at?
Against models of the same generation (released up to 9 months before and up to 3 months after it), the best relative results of GPT-5.5 Instant are: SciCode (#19 of 54). The yardstick is its position among the models of that period that took the same test.
Where do the numbers on this page come from?
From the same three sources as the ranking, all openly licensed: Epoch AI (ECI and individual tests, CC BY 4.0), Arena (human-preference ELO, CC BY 4.0) and LiveBench (overall average, CC BY-SA 4.0). ROO3 does not measure any model. When the page shows a figure published by the maker itself, it appears in the written analysis, labeled as the maker's, and never enters the ranking.
Where each number comes from
Epoch AI, "AI Benchmarking Hub". Published at epoch.ai. Data under the CC BY 4.0 licence, reordered by roo3.co.
The Arena (LMArena) leaderboard, from the public lmarena-ai/leaderboard-dataset on Hugging Face, under the CC BY 4.0 licence. We are not affiliated with the Arena.
LiveBench, by the LiveBench team, published at livebench.ai under the CC BY-SA 4.0 license. The overall average is recomputed by roo3.co with the same formula as the website (average of the categories), and those numbers stay under CC BY-SA 4.0. We are not affiliated with LiveBench.
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