AI & engineering
Nobody knows which AI model to pick.
GPT-4.1 came after GPT-4.5 and this is where the entire problem starts
There was a time when model names were actually useful.
GPT-2 became GPT-3, GPT-3 became GPT-4, and without reading a benchmark you could roughly understand what had happened. The number went up, the model was newer, and usually it was more capable.
That logic has almost completely broken.
Today we have model names trying to tell us how intelligent something is, how fast it is, how much it costs, whether it reasons, whether it is meant for developers, whether it is a preview, and sometimes whether it is even the same model underneath the product.
The naming problem looks funny from the outside, but I think it is showing us something deeper about how AI products themselves are changing.
Bigger Numbers Used to Mean Better Models
The old naming system worked because models were mostly presented as generations.
GPT-2 → GPT-3 → GPT-4 made intuitive sense. You did not need to understand the internal architecture to know which one came later. Then the product surface started expanding.
GPT-4o introduced “omni.” GPT-4.5 arrived. Then OpenAI released GPT-4.1 after GPT-4.5, even though 4.1 was newer and better for several developer workloads.
At that point, the number had stopped behaving like a normal version number.
Then One Name Started Carrying Too Much Information
This is where things started getting messy across the industry.
Take a name like Gemini Flash-Lite.
“Gemini” tells you the family. The number tells you the generation. “Flash” tells you it is optimized for speed and cost. “Lite” pushes that further. Then the actual API model may also be stable, preview, latest, or experimental.
Google's own model docs now have to explain these as separate version types because the model name alone is not enough to tell a developer what they are actually calling. Google's Gemini model naming and versioning docs
The name is no longer really a name.
It is becoming a compressed configuration file.
OpenAI Made the Confusion Impossible to Ignore
OpenAI became the easiest company to make fun of because the options kept multiplying.
There was GPT-4o, GPT-4o mini, o1, o3, o3-mini, GPT-4.5, GPT-4.1, GPT-4.1 mini and GPT-4.1 nano. Sam Altman eventually acknowledged the problem himself and said the company deserved to be mocked for its model naming.
But the interesting part is what OpenAI tried next.
When GPT-5 launched, OpenAI described it as a “unified system.” Instead of asking the user to constantly choose between a fast model and a reasoning model, ChatGPT could route the request automatically depending on the task. OpenAI's GPT-5 unified system
By 2026, the ChatGPT model picker had moved even further in this direction: Instant, Thinking and Pro.
That is a very different idea from exposing a list of model names. The product is starting to describe what the user wants rather than what model is underneath it.
Anthropic and Google Have Different Versions of the Same Problem
Anthropic's system initially feels cleaner.
Opus means the high-end model, Sonnet sits in the middle, and Haiku is optimized for speed. Those names actually communicate something.
But once generations and API versions are added, the hierarchy gets less obvious. Anthropic's current docs can show models such as Fable 5.1, Opus 5.5, Sonnet 5.5 and Haiku 4.5 beside each other, while developers also need to understand aliases, pinned model IDs and older dated snapshots. Anthropic's current model lineup and IDs
Google has Pro, Flash and Flash-Lite. Anthropic has Fable, Opus, Sonnet and Haiku. OpenAI has increasingly moved toward user-facing modes such as Instant and Thinking.
Different naming systems, but they are all trying to solve the same underlying problem.
Models Are No Longer One-Dimensional
This is the part I think matters more than the funny names.
Imagine two models.
Model A is smarter but takes 30 seconds to answer. Model B is slightly less capable but responds in one second and costs one-tenth as much.
Which one is better?
There is no single answer anymore.
For a coding agent you may want deeper reasoning. For autocomplete you care about latency. For processing ten million documents, cost suddenly matters much more. For voice, latency matters differently again.
Now add context length, multimodality, tool use, reasoning effort and specialization.
A single version number cannot describe all of these dimensions at once.
That is why the names keep getting longer. The labs are trying to turn a multidimensional product into a one-dimensional label.
The Model Picker Is Becoming a Product Problem
For developers, complexity is sometimes useful because we actually want control over the exact model, snapshot, price and behavior.
For a normal user, most of this is implementation detail.
Someone trying to summarize a PDF should not need to understand whether they need Sonnet, Haiku, Flash, Thinking, mini or nano first.
And once users have to read articles explaining which model they should select, the naming problem has stopped being a branding problem.
It has become UX.
OpenAI's move toward Instant, Thinking and Pro is interesting because it accepts this. Instead of teaching everyone the model taxonomy, the product can increasingly hide it.
The Future May Be Fewer Model Names, Not Better Ones
I don't think the industry is eventually going to discover the perfect naming system.
There are simply too many dimensions now.
Developers will probably continue seeing specific model IDs because reproducibility, pricing and control matter. But for most users, the model itself may slowly disappear behind the product.
You ask for something. The system decides how much reasoning it needs, which model should handle it, and how much compute is worth spending.
In that world, the model name becomes infrastructure.
And maybe that is where this was always heading.
The real solution to confusing model names may be that most people eventually stop needing to know them.