Is GPT-5 the Best Coding AI Yet?

So... OpenAI has finally pulled back the curtain on its latest model, GPT-5. They released the model on August 7, 2025, marking it as their new flagship model and replacing previous versions. The best part, just like 4o, it's available to all ChatGPT users, both free and paid, though those on Plus and Pro tiers get higher usage limits and access to specialized variants like GPT 5 pro and naturally, I had to put it to the test.

What is GPT-5, According to OpenAI?

Firstly let's look at how OpenAI is officially describing their new model. By what they said, this isn't just a minor update, they're positioning it as a major leap forward. Before we get into the actual briefing on the mode, one line caught my attention was when Sam Altman said:

Now this isn't the first time they're saying this, when OpenAI released the o1 series, they said the same thing, and I even wrote an article highlighting that part of it being likened to someone with a PhD, and even though the way both models work is completely different, for me it just seemed wild how he made it seem as if that's a unique thing for GPT 5 even though it's the same line they used for o1.

From the OpenAI blog “Introducing GPT-5”, they say:

“GPT-5 is our strongest coding model to date. It shows particular improvements in complex front-end generation and debugging larger repositories.”
“It can often create beautiful and responsive websites, apps, and games with an eye for aesthetic sensibility in just one prompt, intuitively and tastefully turning ideas into reality.”
“Early testers also noted its design choices, with a much better understanding of things like spacing, typography, and white space.” OpenAI

From another official OpenAI page:

“As a coding collaborator, GPT-5 tackles complex tasks end-to-end and delivers more readily usable code, better design, and is more effective at debugging.” OpenAI

From the “GPT-5 and the new era of work” blog (OpenAI, August 7, 2025):

“Today we’re introducing GPT-5, OpenAI’s smartest, fastest, most useful model yet, and a major step towards placing intelligence at the center of every business.”

So in human language, it’s the most powerful and polished GPT so far, backed by some solid data and real-world use cases.

My Test

To see how GPT-5 stacks up against the other top of the line AI models, I decided to do a simple test, asking them to code tic tac toe. I gave the exact same prompt to four models: GPT-4.1, Gemini 2.5 Pro, Claude Sonnet 4, and the new GPT-5.

The prompt was simple and a little vague on purpose:

"Can you code tic tac toe in python with a full and intuitive UI"

Here’s what each of them came back with.

GPT 4.1

GPT-4.1 delivered a functional but very basic version of the game. The UI was a simple GUI with a black and white palleette and simple to use. The code itself was the shortest of the bunch, focusing purely on the game's logic. It was a Player vs. Player (PVP) game only, with no option to play against the computer.

My Take: Honestly, it did exactly what you'd expect from such a simple and all rounder model. It understood the core request and delivered a working product. But it didn't take any creative liberties with the "intuitive UI" part of the prompt. It’s reliable, but it’s the bare minimum.

Gemini 2.5 Pro

Gemini 2.5 Pro was a "step up". It also produced a game with a simple GUI, but it immediately understood that "intuitive UI" could mean more than just a functional grid. It used colour to differentiate the players (X and O) and to highlight whose turn it was, which made the game feel more dynamic and, well, intuitive. It was still only a PVP game, but the user experience was noticeably better than GPT-4.1's output.

My Take: This was a solid effort. Gemini showed that it could interpret the subtle intent behind the prompt. The addition of colour might seem small, but it shows a better grasp of user experience. A good, practical improvement over the baseline.

Claude Sonnet 4

This is where things got interesting. Claude Sonnet 4 was the most ambitious of the lot. It generated a game with the best-looking UI by far, complete with a sleek dark mode theme and clear separation of elements. It even included both PVP and a Player vs. Computer mode. I was ready to declare it the winner based on visuals alone.

Then I tried to play it.

The game was completely broken. It would say it was X's turn, but when you made a move, it would place an O on the board. Even worse, it would declare a winner incorrectly, often ending the game after a move like "XXO" was on the board.

My Take: This was a case of style over substance. It built a beautiful car with no engine, literally. It's impressive that it tried to implement a PvC mode and a sophisticated UI, but it failed on the most critical part: making the game work. It was a beautiful failure.

GPT 5

Finally, the new kid on the block. GPT-5 didn't go for the flashy UI like Claude. Instead, it delivered a clean and simple graphical UI that was almost the same as the GPT 4.1 and Gemini ones but with a better implementation. More importantly, it delivered a fully functional game with both PVP and a working Player vs. CPU mode right out of the box.

The most fascinating part was it added features I didn't even ask for, undo, CPU difficulty, alternating between who the first player is, and the standout one, a "hint" button. I'm still not entirely sure what the hints were for or how they were generated but the fact that it added a novel, functional feature without being prompted shows a different level of thinking or processing.

My Take: This is where you see the leap. GPT 5 understood the assignment perfectly. It delivered a functional, intuitive UI and added modes that a user would logically want. The code was clean, and everything worked flawlessly. It was the clear winner.

Conclusion

So, is GPT-5 the king? For this test, absolutely. It delivered the most complete and functional product from a single prompt.

However, the experiment also showed something else. With the right prompts, some patience, and attention to detail, you can get incredible results from all of these models too. Claude Sonnet 4's attempt, while flawed, showed incredible potential for UI design. Gemini 2.5 Pro created a solid, user-friendly experience.