Large language models (LLMs) have demonstrated strong potential in graphical user interface (GUI) generation, but reliable evaluation remains challenging due to uncontrolled data distributions, noisy annotations, and limited layout scenario coverage. To address this, we propose SchemaGUI, a template-based benchmark for controllable GUI generation evaluation. By synthesizing paired natural language instructions and deterministic function-call references from parameterized interface schemas, SchemaGUI can generate thousands of deterministically annotated tasks in seconds without human labeling. Based on 1,000 evaluated instances per scenario and language across six representative bilingual scenarios, we benchmark five mainstream models, including the Qwen3.5 family, Qwen3-Coder-30B, and DeepSeek-R1. Our extensive analysis reveals three key insights. First, precise geometric spatial control remains an important bottleneck; while scaling Qwen3.5 from 4B to 27B improves Schema Feasibility from 91.56% to 99.63%, the Geometry score improves more modestly (from 67.05% to 75.30%). Second, generation difficulty is highly sensitive to layout complexity, with current LLMs excelling at simple sequential arrangements but suffering severe coordinate drift in dense grids and multi-region compositions. Third, thinking mode increases token consumption while generally reducing GUI Score, particularly for smaller models.
Figures & tables
Figure 1: Comparison of different data construction paradigms for GUI generation evaluation. (Left) Web-Crawled : data distribution is uncontrolled with expensive manual annotations. (Middle) LLM-Synthesized : the data distribution remains unknown while outputs suffer from model noise and hallucinated references. (Right) SchemaGUI (Ours) : parametric slot configurations enable enumerable distributions and deterministic, exact annotations.
Figure 2: Overview of the SchemaGUI benchmark. Stage 1 samples a GUI instance s from the schema-driven design space S . Stage 2 constructs the aligned triplet (x,yT,yL) through instruction realization, deterministic reference generation, and model prediction. Stage 3 assigns zero to schema-infeasible predictions and computes the GUI Score for feasible predictions over five evaluation dimensions.
Model
Lang.
Calculator
Login Form
Music Player
Doc Editor
Image Editor
Info Card
Overall
Qwen3.5-4B
EN
33.25
84.58
77.84
87.34
74.97
82.59
73.43
ZH
56.26
89.92
84.20
78.79
65.35
84.71
76.54
Qwen3.5-9B
EN
43.40
85.14
87.51
88.88
64.26
83.77
75.49
ZH
63.22
90.25
88.24
79.53
67.24
78.74
77.87
Qwen3.5-27B
EN
71.93
93.07
88.49
88.85
80.84
84.51
84.61
ZH
74.82
93.10
86.03
81.38
70.81
84.55
81.78
Table 1: Main GUI Score results (%) across six GUI generation scenarios. EN and ZH denote the English and Chinese evaluation sets, respectively. Overall is the macro-average over the six scenarios, with each scenario weighted equally. Within each language, the best result in each column is shown in bold , and the second-best is underlined .
Figure 3: GUI Score across the six GUI generation scenarios, macro-averaged over the five evaluated models and two language settings. The horizontal lines indicate the minimum and maximum scores observed for each scenario.
Model
G
F
T
O
H
Feas.
English (EN)
Qwen3.5-4B
68.52
95.55
86.34
84.38
70.10
86.07
Qwen3.5-9B
73.33
94.68
86.15
82.07
70.40
88.68
Qwen3.5-27B
77.37
99.57
88.19
85.34
74.97
99.37
Qwen3-Coder
72.98
99.99
87.08
82.20
72.12
99.83
DeepSeek-R1
79.09
99.20
87.01
84.03
74.28
87.65
Table 2: Submetric performance (%) and Schema Feasibility (Feas.) in EN and ZH. Submetrics are averaged over schema-feasible predictions. Best and second-best results within each language are shown in bold and underlined , respectively.
Model
Lang.
Calculator
Login Form
Music Player
Doc Editor
Image Editor
Info Card
Overall
Qwen3.5-4B -
EN
2525.9
283.4
591.6
318.7
297.7
192.9
701.7
ZH
1252.4
198.3
329.7
285.2
324.9
146.7
422.9
Qwen3.5-4B +
EN
9022.0
3625.2
4094.8
4570.7
5409.7
3232.2
4992.4
ZH
10181.8
4569.9
4607.1
5563.1
5612.4
4275.3
5801.6
Qwen3.5-9B -
EN
1991.9
309.6
393.1
340.1
298.0
192.9
587.6
ZH
1427.6
299.6
426.1
376.6
447.4
203.5
530.1
Table 3: Average raw response-token consumption ( Tout ) across six GUI generation scenarios. EN and ZH denote the English and Chinese evaluation sets. Superscripts - and + indicate non-reasoning and reasoning-enabled configurations, respectively. Overall is the macro-average across the six scenarios. Within each language, the lowest and second-lowest values are shown in bold and underlined.
Figure 4: Changes in GUI Score after enabling thinking mode for the Qwen3.5 models. Each value denotes Δ=GSthinking−GSno-thinking in percentage points; negative values indicate performance degradation.
Table 4: Main sources of controlled variation across the six SchemaGUI scenarios.
Figure 5: Illustration of the Geometry score and its three penalty sources.
Scenario
G at 0.5
Min. G
Max. G
Range
Calculator
0.51070
0.51060
0.51074
0.00014
Login Form
0.82953
0.82947
0.82953
0.00007
Music Player
0.67393
0.67304
0.67398
0.00094
Doc Editor
0.81896
0.81704
0.81896
0.00191
Image Editor
0.66628
0.66598
0.66661
0.00063
Info Card
0.67729
0.67620
0.67730
0.00110
Appendix
Table 5: Sensitivity of Geometry to the severe-overlap threshold. The threshold is varied from 0.1 to 0.9 in increments of 0.1 . The symbol G denotes the average Geometry score. Results are averaged over the five evaluated models in both EN and ZH settings, with 1,000 samples per model, language, and scenario.
Figure 6: Representative error cases in the Calculator scenario. (a) A schema-infeasible output receives a GUI Score of zero. (b) A schema-feasible prediction suffers from grid collapse, severe out-of-bounds placement, and duplicated controls. (c) A structurally complete and usable prediction retains a relatively high GUI Score despite coordinate and size deviations from the deterministic reference.
Model
Lang.
Calculator
Login Form
Music Player
Doc Editor
Image Editor
Info Card
Qwen3.5-4B -
EN
692–6778
18–3406
18–3574
192–500
291–325
149–238
ZH
112–5741
141–400
239–3649
196–521
297–515
109–189
Qwen3.5-4B +
EN
5433–11715
0–7832
2570–7713
2302–7815
3556–7686
1161–7812
ZH
5242–12480
2438–8735
3172–8521
3741–8418
3615–8194
2334–8951
Qwen3.5-9B -
EN
664–4463
162–525
225–3453
192–620
291–326
149–238
ZH
650–7199
199–579
335–515
278–540
434–596
153–259
Appendix
Table 6: Observed minimum–maximum ranges of raw response-token counts. This table includes all generations, including failed, empty, and timed-out outputs. A minimum of zero indicates that at least one sample produced no recorded raw response tokens. Superscripts - and + denote non-reasoning and reasoning-enabled configurations, respectively.
Model
Lang.
Calculator
Login Form
Music Player
Doc Editor
Image Editor
Info Card
Overall
Qwen3.5-4B -
EN
1278.6
182.3
285.3
254.5
297.7
192.9
415.2
ZH
873.8
194.7
309.0
264.5
324.9
146.7
352.3
Qwen3.5-4B +
EN
193.4
154.2
175.6
220.0
183.6
178.8
184.2
ZH
1293.6
173.3
282.2
322.8
369.7
145.4
431.1
Qwen3.5-9B -
EN
1118.6
185.6
291.1
256.4
298.0
192.9
390.4
ZH
1241.3
278.4
426.1
376.6
447.4
203.5
495.5
Appendix
Table 7: Average clean JSON-token counts for successfully parsed GUI outputs. Clean-token statistics include only valid generations that can be parsed into GUI specifications, while parse-failed, empty, and timed-out outputs are excluded. Overall is the macro-average across the six scenarios.
Model
Render
Fidelity
Layout
Visual
Human
Qwen3.5-4B
72.50
3.86
3.38
2.91
49.06
Qwen3.5-9B
88.30
4.02
3.34
2.68
59.10
Qwen3.5-27B
94.19
4.16
3.93
3.42
72.28
Qwen3-Coder
100.00
4.41
3.69
3.18
75.20
DeepSeek-R1
90.80
3.70
3.33
2.91
60.18
Appendix
Table 8: Human evaluation results across five models. The best and second-best results are highlighted in bold and underlined, respectively.
University of Chinese Academy of Sciences (UCAS) · 2New Laboratory of Pattern Recognition (NLPR), CASIA · 3State Key Laboratory of Multimodal Artificial Intelligence Systems (MAIS), CASIA +3