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Banja Lab / Benchmarks / Test

CODE-0004Programming · easy

Roman numeral conversion both ways

The same task, run on 28 models. Compare the outputs side by side, or open any one in a popup to inspect it.

Top result: claude-opus-4-8 (high reasoning) at 100.0% composite. Lowest: claude-opus-4-8 at 0.0%. 28 models compared on this task.

How it ran
  • Each model was given the brief below in a fresh, isolated session with no access to our tools, and returned its answer from scratch.
  • The rendered output was scored 1 to 5 on brief fidelity, visual design, craft, and impact by a four-family vision panel - Anthropic (Claude Opus 4.8), OpenAI (GPT-5.5), Google (Gemini 3.1 Pro), and xAI (Grok 4.3) - using one identical prompt so the scores compare. The published judge score is leave-one-family-out: a model is never scored by a judge of its own family, so same-family self-preference is removed.
The brief

Implement two Python functions that convert between integers and Roman numerals, using canonical (subtractive) notation. - `int_to_roman(n)`: convert an integer in the range 1..3999 inclusive to its canonical Roman numeral string. Use subtractive forms: 4 is "IV", 9 is "IX", 40 is "XL", 90 is "XC", 400 is "CD", 900 is "CM". Raise `ValueError` for any integer outside 1..3999. - `roman_to_int(s)`: convert a canonical Roman numeral string back to its integer value. Raise `ValueError` for an empty string or a malformed or non-canonical numeral (for example "IIII", "VX", or "ABC"). The two functions are inverses on 1..3999: `roman_to_int(int_to_roman(n)) == n`. Use only the Python standard library. Write your solution to `solution.py`.

Anthropicclaude-opus-4-8
High reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
Anthropicclaude-opus-4-8
Extra-high reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
Anthropicclaude-opus-4-8
Max reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
Anthropicclaude-sonnet-4-6
High reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
Anthropicclaude-sonnet-5
High reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
Anthropicclaude-fable-5
High reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
Zhipuglm-5.2
default reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
Moonshotkimi-k2.7-code
default reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
OpenAIgpt-5.5
High reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
OpenAIgpt-5.5-pro
High reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
OpenAIgpt-5.4-mini
High reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
Googlegemini-3.1-pro-preview
High reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
Googlegemini-3.5-flash
default reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
Googlegemini-3.1-flash-lite
default reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
xAIgrok-4.3
default reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
xAIgrok-4.20-reasoning
default reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
xAIgrok-build-0.1
default reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
xAIgrok-composer-2.5-fast
default reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
Anthropicclaude-sonnet-4-6
High reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
Anthropicclaude-sonnet-5
High reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
Anthropicclaude-fable-5
High reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
Anthropicclaude-haiku-4-5
default reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
DeepSeekdeepseek-v4-pro
default reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
DeepSeekdeepseek-v4-flash
default reasoning
Composite 100.0%Objective 100.0%
Open outputFull run
Anthropicclaude-opus-4-8
Low reasoning
Composite 0.0%Objective 0.0%
Open outputFull run
Anthropicclaude-opus-4-8
Medium reasoning
Composite 0.0%Objective 0.0%
Open outputFull run
Anthropicclaude-haiku-4-5
High reasoning
Composite 0.0%Objective 0.0%
Open outputFull run
Anthropicclaude-opus-4-8
High reasoning
Composite 0.0%Objective 0.0%
Open outputFull run