How to Figure Out Why Perplexity Removed GPT-4.5

Key takeaways:

• GPT-4.5 got removed because it was too slow and expensive.
• Perplexity now uses auto mode by default, but you can still pick models manually.
• The UI and features are changing a lot, so expect some bugs and new stuff.

Ever tried to use GPT-4.5 on Perplexity and wondered where it went? You’re not alone. The CEO of Perplexity dropped some real talk on Reddit, clearing up what’s going on with the models, modes, and why GPT-4.5 disappeared. I’m breaking it down so you don’t have to scroll through endless threads or guess what’s up.

If you want the full rundown straight from the source, here’s the video:
https://www.youtube.com/watch?v=97VR30oCJdQ

Perplexity’s Model Shuffle and Why It Matters

Perplexity’s been making big changes lately. The default mode is now auto, which means the AI picks what model or mode you get. If you’re used to picking your favorite model every time, this might throw you off. But don’t stress—you can still pick the model you want if you switch out of auto mode.

The main reason for this shift? Speed and efficiency. Auto mode lets the AI decide the best way to answer your question, so responses come faster (at least in theory). But if you’re like me and want more control, you can always pick pro or reasoning mode and select the model yourself.

Where Did GPT-4.5 Go? The Real Reason

So, about GPT-4.5. When it first dropped, Perplexity let users try it out with a limited number of daily credits. But it vanished pretty quick. The official word is that GPT-4.5 was just way too slow—only about 11 tokens per second. Compare that to GPT-4o or Sonar, which are much faster.

But here’s the thing: it’s not just about speed. GPT-4.5 is also super pricey. We’re talking $150 per 1 million tokens, while GPT-4o is more like $1–2 for the same amount. Even with just a handful of daily credits, running GPT-4.5 for everyone would burn through Perplexity’s budget in no time. So, yeah, it’s gone because it’s both slow and expensive.

How Model Selection Works Now

The new UI splits models by category. For example, reasoning models are only available in the reasoning menu. If you want to use something like Sonar or Claude 3.7 Sonnet, you’ll find those under pro mode. It’s a little more organized, but it can be confusing if you’re used to the old way.

If you want to see how to change default settings or pick a model, check out this guide on how to change default browser on Android. It’s not the same thing, but it gives you a feel for how to tweak settings when the UI changes.

Deep Research, Code Execution, and What’s Next

Perplexity’s working on making its Deep Research agent smarter, even if it takes longer to get a result. They’re also trying to add code execution, so you could see code previews right in your chat. This is similar to what you get in other AI tools, but it’s a big deal for Perplexity users.

There’s a lot of rewriting happening behind the scenes, too. The team is switching programming languages to make the platform more scalable, which should mean fewer bugs and more features down the line.

Why Follow-Ups Go Back to Auto Mode

If you use reasoning or deep research for a question, any follow-up defaults back to auto mode. Some users hate this, but you can always switch back to your preferred mode. It’s a minor annoyance, but it’s there.

UI Bugs and Missing Features

With all these changes, the UI is a little buggy right now. Some features go missing, then come back. That’s because Perplexity is adding new stuff and trying to make the answer experience more like Google, with menus and navigation for different types of searches.

If you’re running into issues, sometimes a quick restart or clearing your cache helps. For browser problems, how to reset Google Chrome to its default settings might save you some headaches.

Money and IPO Rumors

People have been asking if Perplexity is running out of cash or trying to look good for an IPO. The CEO says finances are solid and there’s no plan to go public until 2028. The recent changes aren’t about prepping for an IPO—they’re about making the product better and more transparent.

What’s Next for Perplexity

Expect more updates, more features, and yeah, probably more bugs for a while. The team’s focused on making things smoother and adding stuff like image generation in the future. If you want to keep up with changes, check the comments on the CEO’s Reddit post—he’s actually answering questions there.

If you’re curious about how to use other AI models or want to try new tools, check out how to unlock the power of GPT-4.

FAQs

Why did Perplexity remove GPT-4.5?

GPT-4.5 was too slow and too expensive to run for everyone.

Can I still pick which AI model I use?

Yes, just switch out of auto mode and you can pick the model you want.

Why does the UI keep changing?

Perplexity is updating features and adding new stuff, so the UI is a work in progress.

What if my favorite model is missing?

Check under different modes like pro or reasoning—models are now grouped by type.

Is Perplexity running out of money?

No, the CEO says finances are good and there’s no IPO until 2028.