This article compares three AI models—Grok 4.5, GPT-5.5, and Claude—by having them build the same applications, highlighting their respective capabilities and differences.
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xAI's latest model Grok 4.5 crushes competitors in code generation speed and cost, but fails on first try for the most complex 3D task; Claude Opus 4.8 and Fable 5 show the highest first-attempt success rates.
TryAI subjected Grok 4.5, GPT-5.5, Claude Opus 4.8, and Claude Fable 5 to three identical code generation tests: building a 3D Rubik's cube (with scramble and solve animation), a particle gravity sandbox, and a Breakout game. All outputs are single-file HTML with no external libraries or network calls. Each model gets only one attempt, with one retry allowed if the app fails to render at all. Additionally, an SVG creative task was included: draw "a horse riding on an astronaut's back walking on the moon."
In the most challenging 3D cube task, Claude Opus 4.8 and Fable 5 generated correctly colored, animated 3D cubes on the first try. Grok 4.5's first attempt rendered only a title and buttons, with the cube area blank; after a retry, the second attempt succeeded. GPT-5.5 rendered only a dim single face, failing to form a complete cube. The two Claude models tie for first place in this task.
In the particle gravity sandbox task, all models produced working applications. GPT-5.5 won for generating the most visually stunning effects (glowing neon attractors, dense colorful trails); Grok 4.5 presented a clean orbital style; Fable 5 leaned toward soft glowing spheres; Opus 4.8's particle field was busiest but visually less appealing. In the Breakout game, all models produced playable games with scores, lives, and glowing paddles on the first try, performing equally.
In a fixed-prompt test (three prompts, three repetitions each, output capped at 400 tokens), Grok 4.5 achieved a median latency of 2.8s, first-token latency of 0.44s, throughput of 110 tok/s, and cost of $0.002 per reply, best in all four metrics. GPT-5.5 had a median latency of 2.0s (fastest for short answers), but first-token latency of 1.26s, throughput of 53 tok/s, and cost of $0.004. Claude Opus 4.8 had a median latency of 2.6s, throughput of 47 tok/s, and cost of $0.004. Fable 5 was the slowest and most expensive: median latency 6.3s, first-token 3.47s, throughput 28 tok/s, cost $0.009. All models achieved 100% success rate. Grok 4.5's P95 latency is about 9s, showing tail latency variability.
In the SVG creative task, Fable 5 performed best: it generated a humorous scene with a horse wearing a cowboy hat shouting "Giddy-up, human!" and a bent-over astronaut gasping. GPT-5.5 came second, with a cheerful horse expression. Grok 4.5 produced a colorful, readable scene. Opus 4.8's SVG contained duplicate attributes, which would cause errors under a strict parser. Overall, Grok 4.5 has clear advantages in speed and cost, but fails on the most complex task on the first try; Claude models lead in reliability, but at the cost of higher latency and cost.
This article is based on a single test by TryAI with a limited sample size (three coding tasks plus one SVG task per model), and the test environment may not fully represent real production scenarios. Speed and cost data were measured by TryAI and have not been independently verified by third parties. Model versions (Grok 4.5, GPT-5.5, Claude Opus 4.8, Fable 5) were the latest at the time of release, but subsequent updates may alter performance.
Grok 4.5 sets a new benchmark in code generation speed and cost, suitable for high-throughput, latency-sensitive scenarios; Claude Opus 4.8 and Fable 5 have higher first-attempt success rates on complex tasks, ideal for reliability-critical applications. GPT-5.5 excels in visual creativity but has shortcomings in complex logic tasks.
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