What's New
The biggest change is that you no longer need to switch between GPT-4, Turbo, or o-series models — GPT-5 automatically delivers the best response for your needs.
GPT-5 is the new default model in ChatGPT. All your requests in ChatGPT are now handled by GPT-5 by default. However, if you reach your usage limit, the GPT-5 mini fallback model will take over. Plus subscribers have more messages, while Pro subscribers have unlimited messages.
There’s a new safe completions system. Now, instead of just saying "no" to requests, like GPT-4 often used to, GPT-5 tries to explain why it can't help you with something specific if it thinks it violates its usage policy. This makes interactions more clear.
Better voice mode. GPT-5 is better at understanding instructions and can adapt its speaking style.
Powerful features for developers. GPT-5 introduces free-form function calling, verbosity control, and three API variants with different price points. The model is really good at Vibe coding and can build full applications from simple instructions.
What stayed the same:
While the new model processes information faster, it maintains a 256K token context window.
There are Three GPT-5 Models
OpenAI released three versions of GPT-5 through its API. Each version is designed for a different need or budget. All versions support both text and vision inputs with a 256K context window and 128K maximum output tokens.
GPT-5 (Standard)
The standard version performs best overall. On SWE-Bench, GPT-5 outperforms GPT-4.1 by 79% on Genspark's Super Agent benchmark, which evaluates how well models can use complex tools and complete tasks from start to finish. For health-related questions, it does much better than older models on HealthBench Hard, but OpenAI says it isn't a replacement for medical professionals.
API cost
$1.25 per million input tokens and $10.00 per million output tokens.
GPT-5 Mini
GPT-5 Mini offers great performance at a low price.
In tests, Mini keeps most of GPT-5's improvements in reducing hallucinations while working much faster. Mercado Libre tested the model and found that the Mini version is 9% more accurate than o4-mini and 36% better than GPT-4.1.
API cost
$0.25 per million input tokens and $2.00 per million output tokens
GPT-5 Nano
The most affordable option, Nano, is best for high-volume, low-latency applications. Even though it's the basic version, it still does better than GPT-4. Allegedly, companies involved in the early tests said this model is the sweet spot for answering customer service questions and doing paperwork.
API cost
$0.05 per million input tokens and $0.40 per million output tokens
GPT-5 Use Case Improvements
Coding
Cursor's team received early access to test GPT-5's coding skills. They found that GPT-5 finds bugs that other models miss and can automatically run background agents to complete complex tasks — a feature that many users already love in Manus.
Vercel also tested GPT-5 on their v0.dev platform. Their findings show that the model is also good at creating user interfaces. It can create user interfaces that look great and work well, and it doesn't need a lot of help from people. This is a big improvement over the previous generation of GPTs, which were known for being bad at making user interfaces that were easy to use.
Research
GPT-5's 256K context window is average for a new model. For example, the Geminini 2.5 Pro has a 1M context window that expands to 2M in thinking mode. However, GPT-5 is much better at remembering things than other AI models.
Box, which tests AI models against complex business documents, calls GPT-5 a "complete breakthrough." Previous models didn't work well when analyzing documents with complex math or logic, but GPT-5 retains information accurately and uses higher-level reasoning to make decisions based on that data. Meanwhile, Notion reports a 15% higher success rate for long-horizon tasks compared to previous models.
Writing
GPT-4 wasn't a very good AI writer. It often used a fake, overly enthusiastic tone. GPT-5 is much better in this regard because it can write in a more natural way that adapts to different tones and formats without explicit instruction.
OpenAI's tests also show that GPT-5 is better at generating accurate technical documents, clear explanations of complex topics, and creative content that is more engaging. Developers can now adjust how detailed the API is. This feature lets them control how many words the model uses to express its thoughts.
In general, AI writing tends to be repetitive, with paragraphs and sentences that are all the same length. However, GPT-5 can produce a lot more variety in sentence structure and paragraph length without any explicit instructions. It's also less likely to lose the tone you want it to use over a long document.
What People Are Saying
As the saying goes, the proof of the pudding is in the eating. Many companies had months to test GPT-5 behind closed doors, and here's what they found.
“The model is able to retain way more of the information that it's looking at, and then use a much higher level of reasoning and logic capabilities to be able to make decisions.”
Aaron Levie, CEO of Box
“It’s hard to believe it’s only been two and a half years since @sama joined us in Redmond to show the world GPT-4 for the first time in Bing, and it’s incredible to see how far we’ve come since that moment.”
Satya Nadella, CEO of Microsoft
“GPT-5 has become our daily driver for everything from scoping and planning PRs to completing end-to-end builds.”
Michael Truell, Co-Founder and CEO of Cursor
“GPT-5 builds on and exceeds o3's advanced reasoning capabilities, enabling developers to tackle more complex problems.”
Thomas Dohmke, CEO of GitHub
How GPT-5 Was Developed and Tested
GPT-5 is the result of a lot of work.
- OpenAI tested the model for 5,000 hours to make sure it was safe to use before releasing it. They focused on making sure it didn't have any harmful outputs, but still kept it useful.
- There's now an improved reasoning engine that evaluates multiple potential responses at the same time before generating output.
- This parallel generation process, combined with chain-of-thought reasoning, helps find mistakes in thinking before they appear in answers. Testing confirmed that this has made the model way more reliable.
- When GPT-5 can't provide accurate information, it now explains its limitations instead of giving incorrect answers that sound plausible.
- OpenAI worked with other companies to test how well it works in the real world. Some of the early users who helped fine-tune the model for the real world were Box, GitHub, and Zendesk. This means the model is much better at helping people solve real problems.
OpenAI says that this joint testing has already made things better, like verbosity control and better tool-calling capabilities. But it would have been nice if they had created a more open space where regular users could also share their ideas.
FAQ
What is GPT-5?
GPT-5 is the newest and most advanced artificial intelligence model from OpenAI, released on August 7, 2025. It's the main model for all ChatGPT interfaces, so you don't have to choose different model versions when using ChatGPT.
What are the main differences between GPT-4.5 and GPT-5?
GPT-5 is a newer model. It reduces hallucinations by 26% compared to GPT-4 series models, processes information faster, and introduces new features like safe completions. Safe completions provide helpful responses within safety boundaries rather than flat refusals. The model also includes a 256K token context window, which allows it to handle long conversations and documents while maintaining accuracy.
What new features does GPT-5 include?
GPT-5 now offers:
- Safe completions for more transparent and helpful responses
- Personalization through personality presets (Cynic, Robot, Listener, Nerd)
- Study Mode for better learning
- Integration with Gmail and Google Calendar for Pro users.
- Free-form function calling
- Verbosity control
- Improved voice mode that better understands instructions
When did OpenAI release GPT-5?
OpenAI officially released GPT-5 on August 7, 2025. Anyone who uses ChatGPT, including Free, Plus, Pro, and Team subscribers, can immediately use GPT-5. Customers with Enterprise and Education plans got access about a week after the initial launch.
What are the key differences between OpenAI's GPT-5 and Google's Gemini AI?
While both are advanced AI models, GPT-5 is different because it uses a unified model approach. This approach eliminates the need to choose between different versions. GPT-5. OpenAI's model can work better with other business software. Companies like Microsoft, GitHub, and Box are using it to do new things that other models couldn't do before. But this probably won't matter to most users.
Bottom Line
GPT-5 isn't a complete game changer, perhaps, but it's a big upgrade from GPT-4. It's more reliable, and it's great to have one model that's good at coding and creative tasks. We've seen a similar trend from Claude models, which can also be called "jack of all trades," and they are very popular with users.
We are still in the early stages of testing, and it will take some time for OpenAI to fine-tune the model. The quality of responses may change over the next couple of weeks, for better or worse — that remains to be seen.
Even so, GPT-5 seems to reach a point where AI becomes truly useful for complicated tasks that used to require constant human supervision and correction. We're excited to see how this will develop.
