# Generative UI framework benchmark

Canonical page: https://www.openui.com/benchmarks/framework

## What this benchmark answers

How do OpenUI, Google A2UI, and Vercel json-render compare under the same briefs and generation condition?

## Scope and condition

- 46 interface briefs, 6 models, 3 formats, and four generations per brief.
- 1,104 runs per format; 3,312 scored runs in total.
- 16,384-token output ceiling, temperature 0.7 where supported, and minimal or no reasoning.
- Each format uses its own SDK-generated prompt and shipped validation, plus the same shared completeness layer and component-count floor.
- Every row is scored by one build of the shipped OpenUI parser, lang-core 0.2.16.

## Format summary

| Format | Structural validity | Render success | Blank screens | Runs |
| --- | ---: | ---: | ---: | ---: |
| OpenUI | 96.9% | 99.9% | 1 | 1104 |
| A2UI | 95.6% | 96.6% | 37 | 1104 |
| json-render | 82.8% | 99.6% | 4 | 1104 |

## Results by model and format

| Model | Format | Valid runs | Structural validity | Render success | Cost per 46-screen pass |
| --- | --- | ---: | ---: | ---: | ---: |
| GPT-5.6 Sol | OpenUI | 183/184 | 99.5% | 100.0% | $3.08 |
| GPT-5.6 Sol | A2UI | 177/184 | 96.2% | 97.3% | $6.84 |
| GPT-5.6 Sol | json-render | 152/184 | 82.6% | 100.0% | $6.30 |
| Claude Opus 4.8 | OpenUI | 182/184 | 98.9% | 100.0% | $2.27 |
| Claude Opus 4.8 | A2UI | 183/184 | 99.5% | 100.0% | $5.85 |
| Claude Opus 4.8 | json-render | 161/184 | 87.5% | 100.0% | $4.88 |
| Kimi K3 | OpenUI | 177/184 | 96.2% | 100.0% | $1.53 |
| Kimi K3 | A2UI | 176/184 | 95.7% | 97.3% | $3.16 |
| Kimi K3 | json-render | 131/184 | 71.2% | 100.0% | $2.91 |
| Gemini 3.7 Flash | OpenUI | 182/184 | 98.9% | 100.0% | $0.42 |
| Gemini 3.7 Flash | A2UI | 173/184 | 94.0% | 96.7% | $0.95 |
| Gemini 3.7 Flash | json-render | 171/184 | 92.9% | 100.0% | $0.85 |
| Qwen3.8 2.4T | OpenUI | 169/184 | 91.8% | 99.5% | $0.81 |
| Qwen3.8 2.4T | A2UI | 168/184 | 91.3% | 91.3% | $1.90 |
| Qwen3.8 2.4T | json-render | 149/184 | 81.0% | 97.8% | $1.46 |
| Muse Spark 1.2 | OpenUI | 177/184 | 96.2% | 100.0% | $0.71 |
| Muse Spark 1.2 | A2UI | 178/184 | 96.7% | 97.3% | $1.38 |
| Muse Spark 1.2 | json-render | 150/184 | 81.5% | 100.0% | $1.34 |

## Links

- Methodology: https://www.openui.com/benchmarks/methodology
- JSON: https://www.openui.com/benchmarks/framework/data.json
- CSV: https://www.openui.com/benchmarks/framework/data.csv
- Raw results for the published scorer regime: https://github.com/thesysdev/generative-ui-bench/tree/main/results
- Combined benchmark: https://www.openui.com/benchmarks