When Google launched Gemini Ultra, the benchmarks claimed it beat GPT-4 on most metrics. Benchmarks are nice. I wanted to know if it actually performs better on the tasks I do every day. So I ran 30 real tests across coding, writing, analysis, and math. Here's what I found.
The setup
I used Gemini Advanced (Ultra 1.0) through the web interface and GPT-4 through ChatGPT Plus. Same prompts, no system instructions, clean sessions for each test. I scored each response as a win, loss, or tie based on accuracy, usefulness, and completeness. This isn't a scientific benchmark. It's a practical comparison from one developer's perspective.
Coding: GPT-4 wins 8-5
I tested function generation, debugging, code explanation, refactoring, and API integration across Python, JavaScript, and Go. GPT-4 won most of the coding challenges, but not by the margin I expected.
GPT-4 was consistently better at generating working code on the first attempt. Its solutions compiled and ran correctly more often. Gemini had a tendency to produce code with small errors, missing imports, wrong method names, and occasionally using syntax from the wrong language version.
Where Gemini surprised me was in code explanation. When I pasted complex code and asked for a walkthrough, Gemini's explanations were sometimes clearer and better structured than GPT-4's. It broke things down more methodically. For a learning use case, Gemini's explanations might actually be preferable.
Writing: Gemini wins 6-4
This was the genuine surprise. I tested technical blog posts, documentation, email drafting, and summarization. Gemini produced more natural-sounding text with better flow. GPT-4's writing has a recognizable pattern that's starting to feel formulaic, the "certainly" and "it's worth noting that" constructions that scream AI.
Gemini's writing felt fresher. Less template-driven, more varied sentence structure. For documentation specifically, Gemini produced output that needed less editing before I'd consider publishing it. GPT-4 was better at maintaining a consistent tone across long documents, so for anything longer than 1,000 words, GPT-4 held together better.
Analysis: Tie at 4-4
I tested data analysis (given a dataset, find insights), technical comparison (compare two architectures), and decision-making (given these constraints, what should I choose). This was the closest category. Both models are genuinely good at analytical reasoning.
GPT-4 was better at structured quantitative analysis. When I gave it numbers and asked for calculations, it was more reliable. Gemini was better at qualitative analysis and identifying non-obvious considerations. It would surface risks and tradeoffs that GPT-4 glossed over.
Math and logic: GPT-4 wins 5-3
Tested arithmetic, algebra, word problems, logic puzzles, and probability. GPT-4 was more accurate, especially on multi-step problems. Gemini made arithmetic errors more frequently and sometimes lost track of intermediate results in complex calculations.
The one area where Gemini performed better was geometric reasoning. On two spatial/geometric problems, Gemini got the right answer while GPT-4 struggled. Small sample size, but an interesting data point.
Speed and usability
Gemini is faster. Responses generate noticeably quicker than GPT-4, especially for longer outputs. The Gemini interface is cleaner too. Google clearly invested in the UX. But ChatGPT's ecosystem, plugins, code interpreter, DALL-E, is a significant advantage that Gemini doesn't match yet.
Overall: GPT-4 still leads, but Gemini is closer than expected
Final score across all 30 tests: GPT-4 wins 17, Gemini wins 11, ties 2. GPT-4 is still the better overall model, but Gemini isn't the "Google Bard rebrand" that some people dismissed it as. It's a genuinely capable model with specific strengths in writing and qualitative reasoning.
My honest take: if Gemini was the only AI model available, I'd still be very productive. That says something. A year ago, there was only one game in town. Now we have at least three serious contenders (counting Claude), and competition is making everything better.
I'm not switching from my Claude-primary workflow, but Gemini earned a spot in my toolkit for writing tasks and quick analysis. The speed alone makes it worth having as an option when I need fast answers.