Understanding ChatGPT 4.5: The Good, the Bad, the Ugly

Here’s an honest deep dive into OpenAI's latest model, highlighting its strengths, flaws, and everything in between.

While everyone’s busy talking about Claude 2, Gemini 1.5, and open-source beasts like DeepSeek, OpenAI just dropped GPT-4.5 into the wild... without the usual hype. A smoother, smarter, more emotionally aware version of the ChatGPT you’ve been using.

But here’s the thing: even though GPT-4.5 isn’t some massive generational leap like GPT-5 (we’re still waiting on that), it feels like a huge upgrade. Conversations flow better. It makes fewer dumb mistakes. And honestly? It’s the first time that using ChatGPT feels like you’re talking to someone who actually understands you.

So, what exactly is GPT-4.5? How’s it different from GPT-4o and other previous models? And is it even worth the upgrade? 

ChatGPT 4.5: An Overview

So, let’s start with the basics. In classic OpenAI fashion, GPT-4.5 kind of just… showed up. No flashy event, no massive announcement. One day, we were all using GPT-4, and the next, people on Pro plans started noticing a new AI language model with way better responses. That’s GPT-4.5.

Now, don’t expect a revolutionary leap like what we’re hoping for with GPT-5. GPT-4.5 is more of a refined upgrade. Sam Altman even said that this version "finally feels like talking to a smart person." And honestly? He’s not wrong. 

Conversations with GPT-4.5 feel way more natural. It understands what you’re trying to say even if your prompt is a little messy, and it responds in a tone that actually feels thoughtful, like it’s listening. Like it’s got a little personality.

So while it may not break the mold, GPT-4.5 does one thing exceptionally well: it feels human. And that, in the world of AI, is a huge deal.

GPT-4.5 is OpenAI’s Last "Non-Chain-of-Thought" Model

Here’s something not everyone is talking about—but it’s important: GPT-4.5 might be the final model from OpenAI that doesn’t fully embrace the “chain of thought” reasoning method.

Wait—what does that even mean?

“Chain of thought” models are trained to explain their reasoning step-by-step, almost like how a human would talk through solving a problem out loud. This makes their answers more transparent and easier to follow—especially for tasks like math, coding, logic puzzles, or anything else that requires structured thinking.

OpenAI’s next-gen models—like GPT-4o and likely GPT-5—are evolving toward faster, more fluid interactions across text, image, and audio. While they’re fully capable of detailed, step-by-step reasoning, their default responses may lean more conversational or concise unless prompted otherwise. This doesn’t mean they’re less intelligent or explanatory—just that users might need to guide them toward deeper reasoning when needed.

So, if you’re someone who values clarity, detailed breakdowns, and responses that actually show how the model got to an answer, GPT-4.5 might be your last “classic” experience before the next wave of AI changes how reasoning looks altogether.

Features of ChatGPT 4.5: The Improvements Explained!

Let’s talk about what makes GPT-4.5 actually feel like an upgrade—because while it’s not a full-blown reinvention, it brings several meaningful improvements to the table. If you’ve used GPT-4 or even GPT-3.5, you’ll definitely notice the glow-up.

1. Way More Natural Conversations

This is probably the first thing you'll notice: GPT-4.5 just talks better. It gets your tone, flows with your thoughts, and doesn’t sound like a formal chatbot reading from a script. Whether you’re venting about your day, brainstorming product ideas, or writing captions for social media, it keeps up with you without feeling robotic.

To test, I gave a prompt: “Bill Gates said that AI will take over most of the jobs in the future except 3 areas (coders, biologists, and Energy Experts). I think it's kind of messed up and wrong. Give your take on it as a person.”

Compared to GPT-4, the replies (just like this one) in GPT-4.5 felt more fluid, less rigid, and more human-like. Sometimes, it even throws in subtle empathy or humor when the context calls for it.

2. Fewer Hallucinations (Finally!)

Hallucinations—aka AI making stuff up confidently—have been a long-standing issue. GPT-4.5 does a better job of staying grounded.

When I asked it to give some data about the declining user base of Facebook, the ChatGPT model 4.5 gave data from trusted sources (something which it often failed to do before).

Tests show its hallucination rate is lower than both GPT-4o and older models. It’s not perfect (none of them are), but it’s a big step forward. If you use AI for fact-based work—summarizing research, writing reports, or answering questions—this makes a real difference.

3. Better at Holding Context

GPT-4.5 doesn’t forget what you said two prompts ago. It handles long conversations and complex back-and-forths much more smoothly. You can jump between topics or refer to earlier points, and it won’t lose the thread like GPT-3.5 often did. This is especially helpful for brainstorming, storytelling, or building step-by-step guides where you need the AI to "remember" things.

To test this, I entered the below prompt right after the previous one.

Prompt: Which team will win the FIFA 2026 according to you? Give one answer.

After getting the output, I again asked the model a subsequent question about the previous (Bill Gates and AI will eat up jobs) topic.

Prompt: Do you think only these 3 jobs will remain in the future for humans?

  

The model held the memory of the previous conversation spectacularly and jumped back in in no time when I initiated the conversation.

4. Smarter Writing, Less Fluff

GPT-4.5 is noticeably better at structured writing—like emails, resumes, marketing copy, and blog intros (like the one you read above). It gets tone and audience better, and you don’t have to fight with it to stop repeating itself or going off-topic. Compared to GPT-3.5, it’s more direct and confident.

5. More Emotionally Tuned

One of the subtler improvements: OpenAI GPT-4.5 is emotionally smarter. You can say something sarcastic, sad, or playful, and it responds appropriately. It’s not just replying to words—it’s reading the mood. This makes it a better companion for everything - from customer support to creative writing.

ChatGPT 4.5 Performance Benchmark: How Does It Compare?

OpenAI's release of 4.5 has sparked considerable interest regarding its performance across various tasks. To understand the full ChatGPT-4.5 capabilities, it's essential to examine how the model measures up against its predecessors and other models in key areas.

1. Faṣctual Accuracy and General Knowledge

GPT-4.5 shines in factual accuracy. In the SimpleQA benchmark, which tests straightforward knowledge questions, GPT-4.5 achieved a 62.5% accuracy rate. This is a significant leap over GPT-4o's 38.2% and even outperforms OpenAI's o1 model, which scored 47%.

Moreover, GPT-4.5 has a lower hallucination rate of 37.1%, which means it's less likely to generate incorrect information compared to GPT-4o's 61.8%.

2. Complex Reasoning and Problem-Solving

However, when it comes to complex reasoning tasks, GPT-4.5 doesn't perform as well. In the AIME'24 math competition benchmark, it scored 36.7%, which is better than GPT-4o's 9.3% but falls short of the o3-mini model's impressive 87.3%. Similarly, in the GPQA science assessments, GPT-4.5 scored 71.4%, outperforming GPT-4o's 53.6% but again lagging behind o3-mini's 79.7%.

3. Coding and Software Engineering Tasks

Interestingly, GPT-4.5 shows promise in coding tasks. In the SWE-Lancer benchmark, which evaluates performance on real-world programming tasks, GPT-4.5 outperformed both GPT-4o and o3-mini (refer to the figures above). This suggests that while it may struggle with theoretical problem-solving, it can handle practical coding challenges effectively.

4. Multilingual Capabilities

GPT-4.5 also excels in multilingual tasks. Evaluations across 15 languages, including Arabic, Chinese, and Spanish, show that it outperforms GPT-4o in understanding and generating accurate text.

ChatGPT 4.5 Vs ChatGPT 4o: What’s Actually Different?

If you’re wondering whether GPT-4.5 is better than GPT-4o, the answer is: it depends on what you’re using it for. These models have different strengths, and choosing the right one really comes down to how you plan to use ChatGPT. Let’s break it down.

Conversational Flow: Who Feels More Human?

GPT-4.5 wins with flying colors in this area. It’s designed to talk more like a real person—natural, smooth, and emotionally aware. Whether you’re having a casual chat, working on a writing prompt, or even venting about your day, GPT-4.5 feels less like a chatbot and more like a thoughtful friend who actually gets you.

GPT-4o, on the other hand, is more structured. It’s great if you want a step-by-step breakdown or need help with a technical task, but it can come off a little robotic in regular conversation. So, if the “vibes” matter to you, GPT-4.5 takes the win here.

Use Cases: Which One Should You Use?

GPT-4.5 is your go-to if you're:

• Writing content, emails, or essays
• Brainstorming creative ideas
• Looking for a chatbot that actually sounds like a human
• Chatting for fun or general-purpose Q&A

GPT-4o is better if you're:

• Solving math problems or complex logic puzzles
• Writing or debugging code
• Working on tasks that require accuracy and methodical reasoning
• Doing anything highly analytical or structured

So think of it like this: GPT-4.5 is the creative writer or friendly teammate, while GPT-4o is the software engineer who loves rules and precision.

Performance and Accuracy: Who’s Smarter?

Now, this one’s a bit nuanced. GPT-4.5 is definitely smarter when it comes to conversations. It’s less likely to ‘hallucinate’ or make up random facts, which is a huge improvement over earlier versions. It’s also faster and more emotionally intelligent.

But when we’re talking about raw logic and structured problem-solving—like solving tough math equations or writing flawless code—GPT-4o can still outperform it in many cases. It’s just built for that type of work.

What are the Limitations of GPT-4.5?

Alright, now that we’ve hyped up GPT-4.5’s features and how natural it feels, let’s be real. It’s not perfect. Like every model, it has its own set of weaknesses. If you’re thinking about relying on it for serious work, here’s what you should know:

1. Still Struggles with Complex Logic

GPT-4.5 might sound smarter, but when it comes to heavy-duty logical reasoning, like solving multi-step math problems, complex code logic, or scientific puzzles—it’s not always the best pick.

As mentioned above, in benchmark tests like AIME, it scored lower than models like o3-mini, which are more logic-focused. So, if you're looking for a logic wizard, GPT-4.5 might occasionally fumble the ball.

2. Not as Strong in Structured Problem Solving

You’ll notice GPT-4.5 is great at going with the flow—but sometimes, structure suffers because of that. For tasks where you need a clear, step-by-step breakdown (think coding bugs, legal analysis, data interpretation), GPT-4o or other models might give more precise answers. 4.5 can skip steps, give vague justifications, or go off on tangents if you’re not careful with your ChatGPT prompts.

3. Still Hallucinates (Just Less)

Yes, it hallucinates less than GPT-4o—but ‘less’ isn’t ‘never’. It can still confidently give wrong info, invent citations, or mix up dates and facts. If you’re using it for anything research-based or factual, always double-check what it says. Treat it like a smart intern, not a flawless expert.

4. Limited Access (for Now)

As of now, GPT-4.5 isn’t available to everyone. You’ll need a ChatGPT Pro or Plus subscription (with limited credits) to use it. That’s the $200 and $20/month plan, respectively. Free-tier users are still stuck with GPT-3.5. And because OpenAI’s been facing GPU shortages, it might take time before wider access rolls out—even for paying users.

5. Not as Multimodal as GPT-4o

GPT-4.5 focuses mainly on text, so if you're using ChatGPT for image inputs, voice, or full-on multimodal tasks, GPT-4o (or the newer multimodal versions like GPT-4-turbo) might be more capable. GPT-4.5 isn't dumb, but it's not juggling images and audio at the same level.

6. Not the Best Fit for Every Use Case

At the end of the day, GPT-4.5 leans toward creativity and conversation. That’s great for writers, marketers, or anyone looking to brainstorm. But if you're a developer, scientist, or data analyst—you might find it a bit too casual or imprecise for what you need.

Final Thoughts: Should You Care About GPT-4.5?

At the end of the day, GPT-4.5 isn’t here to reinvent the wheel—it’s here to smooth the ride.

If you’re someone who uses AI for writing, chatting, research, or just bouncing around ideas, this model feels like a genuine upgrade. It talks more naturally, makes fewer silly mistakes, and just gets you better. That alone makes it worth your attention.

But here’s the thing—GPT-4.5 might also be the last of its kind. OpenAI is already shifting gears toward models like GPT-5 and whatever’s coming next, which are faster, more intuitive, and multimodal. All I know is that the AI space is changing fast, and GPT-4.5 is a quiet but solid reminder that OpenAI still knows how to lead the game—even when everyone else is shouting louder.