What Is ChatGPT 5? Everything You Need to Know

ChatGPT-5 is the latest, smartest, and most practical model OpenAI has released to date. It has replaced GPT-4o as the new “brain” of ChatGPT. Its biggest change is the removal of manual model selection.

At first, the automatic model switching felt a bit unstable, but OpenAI has been rolling out continuous updates. After several weeks of use, I can clearly feel that ChatGPT-5 is now more intelligent than at launch, delivering more accurate reasoning and fewer hallucinations compared to the GPT-4o era.

In this article, I’ll share my hands-on experience and testing, giving you a detailed look at ChatGPT-5’s core upgrades, features, pricing, and whether it’s worth upgrading.

Overview of ChatGPT-5

Chat GPT 5, released on August 7, 2025, is considered the most powerful version OpenAI has ever developed, being more proficient in coding, reasoning, and complex instruction recognition than 4o.

The core upgrades of this update include: 

• No more manual model switching — just ask a question, and ChatGPT automatically routes to the right module for the most accurate response.

• Stronger multilingual and cross-lingual support, with greater stability and fewer low-level errors on complex projects.

• A massively expanded context window, jumping from 128k tokens to 400k, making it easy to process long documents.

• More reliable reasoning that not only provides accurate answers but also shows its step-by-step process.

• A new proxy mode that can directly organize Gmail emails and help draft strong replies.

• Better-grounded answers, since ChatGPT-5 essentially performs real-time online searches for every response.

Overall, ChatGPT-5 represents one of the biggest upgrades in ChatGPT’s history. The unification of models, improved accuracy, and expanded capabilities are exactly the kind of changes many users had been hoping for.

Core Upgrades of ChatGPT-5

Coming up, we’ll explore GPT-5’s major upgrades and fresh features, and show how they can transform efficiency in both work and study with real cases.

Model Integration

Amid all the rumors surrounding ChatGPT-5, model integration has been the clearest upgrade Sam Altman has hinted at. Back in the GPT-4o era, people were still stuck choosing between 4.5, 4o-mini, or o3. Now, GPT-5 Auto handles it all by automatically routing your question to the right model.

Take this classic Knights and Knaves puzzle as an example:

On an island, every inhabitant is either a Knight (always tells the truth) or a Knave (always lies).

You meet two people:

• Person A says: “At least one of us is a Knave.”
• Person B says nothing.

Question: What are A and B?

It will automatically recognize that this is a complex reasoning problem and enter the corresponding thinking module, presenting me with a complete reasoning process, and finally giving me an answer like this:

Answer: A is a Knight, B is a Knave.

Why:

• Suppose A was a Knave. Then A’s statement “At least one of us is a Knave” would be false, which would mean neither is a Knave—a contradiction (A would then be a Knight). So A cannot be a knave.
• Therefore, A is a Knight, so the statement is true: at least one is a Knave. Since A isn’t, B must be.

Enhanced Reasoning Ability

One of the key highlights of GPT-5 is its improved logical reasoning. As shown in the ‘Knights and Knaves’ puzzle I tested, it not only delivers the right answer but also walks through the solution step by step. 

When discussing reasoning skills, we often look at GPQA Diamond — a benchmark that challenges AI with doctoral-level questions.

As shown in the figure, GPT-5 Pro achieved the top score of 89.4% in the doctoral-level subject exams — almost 20 points higher than GPT-4o’s 70.1%. 

Even more impressive, enabling Thinking mode boosts GPT-5’s accuracy from 77.8% to 85.7%. For learners and researchers, ChatGPT-5 is now far more capable than before.

Stronger Coding Skills

For developers, Claude’s coding has long been ahead of ChatGPT. But with the GPT-5 upgrade, its code generation marks a major step forward — not only stronger in syntax and structure, but also better at understanding context.

To test coding capabilities, ChatGPT was evaluated on SWE-bench Verified and Aider Polyglot. SWE-bench Verified is one of the benchmarks that best addresses the question: “Can AI be a programmer?”, where higher scores reflect stronger coding and bug-fixing skills.

In our ChatGPT benchmark, with Thinking mode enabled, GPT-5 scored 74.9% — 5.8 points higher than o3 (69.1%) and a full 44.1 points higher than GPT-4o. 

GPT-5 also performed strongly on Aider Polyglot, a benchmark that evaluates code generation in multilingual projects. As shown in the figure, GPT-5 achieved 88%, 62.2 points higher than GPT-4o’s 25.8%.

The latest ChatGPT not only features stricter syntax and better contextual understanding but also handles cross-language projects more reliably. In coding benchmarks against Claude and Grok, ChatGPT has nearly caught up. Coding is finally no longer its weak spot.

More Accurate Answers

AI inaccuracies are mainly caused by hallucinations — fabricating content when there’s no factual basis. Users often complained about GPT-4o in this regard. 

However, based on official benchmarks, GPT-5’s hallucination rate is 2.8% — about 20% lower than O3’s 23.5%.

 

From my own experience, GPT-5’s control over hallucinations has clearly improved. When I ask questions, it now automatically searches the web for sources, which makes the information feel more reliable than its own generated answers.

Reduced Flattery

Many users felt that ChatGPT-4o often gave overly flattering answers. In our evaluation, however, its responses were more objective than flattering.

OpenAI’s latest evaluation shows that GPT-5 cut down obsequious responses from 14.5% to under 6%. 

However, many users feel its tone has become less friendly — responses sound more mechanical and lack a ‘human touch.’ Fortunately, OpenAI plans to keep refining its interaction style in future updates, aiming to make it friendlier without raising the hallucination rate.

GPT-5 Keeps Improving

From my own experience, it’s far from ‘set in stone.’ Since its release on August 7, 2025, OpenAI has closely followed user feedback and rolled out dynamic updates to make GPT-5 more capable and user-friendly. Key adjustments include:

• Return of GPT-4o: After GPT-5’s debut, many users reported it wasn’t as user-friendly as GPT-4o in certain cases. OpenAI responded quickly, restoring GPT-4o as an option just a week later.
• New Quick and Thinking modes: The latest version introduced GPT-5 Thinking for more in-depth answers, and GPT-5 Instant for fast, straightforward responses.
• Gradual rollout of new features: At launch, Agent Mode and Connected Apps weren’t fully available. Ongoing updates are bringing them online, steadily making GPT-5 a more complete and user-friendly assistant.
• Improved interaction tone: Some Reddit users felt GPT-5 lacked the ‘warmth’ of 4o. Recent updates have made it sound more human, while still keeping responses objective.

We’re making GPT-5 warmer and friendlier based on feedback that it felt too formal before. Changes are subtle, but ChatGPT should feel more approachable now.

You'll notice small, genuine touches like “Good question” or “Great start,” not flattery. Internal tests show no rise in…

— OpenAI (@OpenAI) August 15, 2025

GPT-5 is still receiving regular updates. If the initial launch didn’t seem very impressive, it’s worth staying tuned. I believe future updates will only make it smarter.

Functional Test of ChatGPT-5

The ChatGPT-5 upgrade introduces several new features — Learning Mode, Agent Mode, app integrations, and cloud storage connectivity. Let’s explore them one by one.

Learning Mode

In Learning Mode, ChatGPT doesn’t just give long text answers — it actively guides you through repeated practice.

For example, if I want to learn trigonometric functions, Learning Mode generates problem-solving cards to reinforce key concepts.

I also uploaded my notes, and ChatGPT adapted its explanations to my progress. For self-learners, ChatGPT-5 is like a patient teacher.

Agent Mode

One of GPT-5’s biggest highlights is Agent Mode — a feature designed to seriously boost productivity. Before, I had to manually research companies, track news, and analyze strategies.

Now, with Agent Mode, I can upload a CSV of 100 companies and let GPT-5 handle the research.

It scanned over 20 websites in seconds and delivered an analysis that would’ve taken me hours. It even added simple animations so the wait didn’t feel dull.

Connect More Applications

GPT-5 now connects directly to popular work tools like Gmail, Slack, Notion, and Trello.

• Slack: Automatically organizes channel discussions, extracts key decisions, and shares them with the team.
• Gmail: Drafts replies in your writing style — just click “Send.”
• Notion: Saves ChatGPT responses to your workspace and builds project wikis.

This makes working with ChatGPT smoother — no need to keep switching between apps and tabs.

Cloud Storage Integration

Another practical upgrade is cloud storage integration. You can now link Google Drive, Dropbox, or OneDrive to access and organize documents directly.

For example: “Find the market survey slides I uploaded to Drive yesterday and summarize them into five key points.” For anyone drowning in documents, this feature saves huge amounts of time by removing manual search and analysis.

ChatGPT-5 Pricing

Globally, OpenAI offers three main ChatGPT-5 subscription plans — Free, Plus, and Pro — designed for different types of users.

• Free Version: Free users can try ChatGPT-5, but with strict limits. Proxy Mode is unavailable, and both Deep Thinking and image generation have tight usage caps.
• ChatGPT Plus: At $20/month, Plus is the most popular plan. It unlocks key GPT-5 features like Deep Thinking and Agent Mode, with far more generous limits than the Free plan.
• ChatGPT Pro: Pro, at $200/month, targets developers and heavy users. It removes usage caps across all features and gives exclusive access to GPT-5 Pro — a more powerful model built for stable performance in coding, reasoning, and professional workloads.

OpenAI is also piloting a budget plan called ChatGPT Go in select markets, starting in India. Priced at just $5/month, it offers a Plus-like feature set at a fraction of the cost, aimed at users with tighter budgets.

ChatGPT Go launches in India!

Looking forward to making ChatGPT more affordable in India first, and then learning from feedback to expand to other countries. https://t.co/NRzXrTB3Mr

— Sam Altman (@sama) August 19, 2025

If you’re outside India, for example, in the US, and want to get ChatGPT Plus for less, you can purchase a shared account through GamsGo. GamsGo lets you use ChatGPT Plus for only $6 a month, nearly 75% cheaper than the official price.

Should You Upgrade to ChatGPT-5 Plus or Pro?

If you just use it casually, for fun or quick everyday questions, the Free plan is more than enough.

If you depend on ChatGPT for work like writing, coding, or research, Plus at $20/month is the sweet spot.

OpenAI has designed the paid tiers to deliver far more value than Free, and many new features like Learning Mode and Agent Mode are locked behind Plus.

Here is how we are prioritizing compute over the next couple of months in light of the increased demand from GPT-5:

1. We will first make sure that current paying ChatGPT users get more total usage than they did before GPT-5.

2. We will then prioritize API demand up to the…

— Sam Altman (@sama) August 12, 2025

Ready to Try ChatGPT-5?

Despite some controversy around its launch, ChatGPT-5 is still one of the most advanced AI assistants today. With big upgrades in reasoning, coding accuracy, and personalization, it shines in writing, learning, programming, and even multimodal AI tasks.

At the end of the day, upgrading comes down to your needs and budget. If you want the latest GPT-5 features at the lowest cost, subscription-sharing platforms like GamsGo can be a smart alternative.

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