OpenAI says GPT-5.5 Instant produces 52.5% fewer hallucinated claims “on high-stakes prompts covering areas like medicine, law, and finance”
- GPT-5.5 Instant is rolling out to all ChatGPT users and to the API. — Enhanced personalization is initially for Plus and Pro on the web.
Axios Megan Morrone
Related Coverage
- OpenAI claims ChatGPT's new default model hallucinates way less The Verge · Jay Peters
- OpenAI releases GPT-5.5 Instant, a new default model for ChatGPT TechCrunch · Ivan Mehta
- I tested GPT-5.5 Instant — and it finally stopped overexplaining everything Tom's Guide · Amanda Caswell
- GPT-5.5 Instant makes ChatGPT more accurate while nixing ‘gratuitous emojis’ 9to5Mac · Zac Hall
- ChatGPT accuracy improves in new model push The Deep View · Sabrina Ortiz
- ChatGPT's Latest Model Will Supposedly Give Less Annoying Answers CNET · Macy Meyer
- ChatGPT's new default model is more factual and better at personalization Engadget · Igor Bonifacic
- ChatGPT launches a CAPI, a pixel, and self-serve Mobile Dev Memo · Eric Benjamin Seufert
- ChatGPT update rolls out GPT-5.5 Instant with fewer hallucinations and more personalized answers The Decoder · Matthias Bastian
- OpenAI Releases GPT-5.5 Instant for ChatGPT With Improved Accuracy and Memory Controls iClarified · Shalom Levytam
- ChatGPT's Goblin Obsession Evades OpenAI's Fixes TidBITS · Adam Engst
Discussion
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@masterwang34
Mole
on x
GPT 5.5 instant: 30% less yap :) [image]
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@jp54362
@jp54362
on x
GPT-5.5 Instant clearly performs better than GPT-5.3 Instant in both science and math tests. In PhD-level science, it improves from 78.5% to 85.6%, which shows stronger understanding of complex topics. In competition math, it jumps from 65.4% to 81.2%. [image]
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@teksedge
David Hendrickson
on x
🚨 New @OpenAI GPT Model Alert: GPT-5.5 Instant is rolling out in ChatGPT. Key upgrades ⚡ Smarter + clearer responses 🗣️ Warmer, more natural tone ✂️ Much more concise (finally!) ✅ Stronger factuality in medicine, law & finance 🧠 Better memory & personalization 💰 API [video]
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@enginron
@enginron
on x
GPT-5.5 Instant really said STEM? I got this. GPQA (PhD Science): 78.5% - 85.6% AIME 2025 (Comp Math): 65.4% - 81.2% Math + science upgrades are getting too real. We're cooked (in a good way) [image]
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@conor_d_dart
Conor Dart
on x
Great to see Gpt 5.5 coming out. I'd still use thinking but could very well be a great model for instant replies
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@mark_k
Mark Kretschmann
on x
GPT-5.5 Instant is currently rolling out in @ChatGPTapp. I'd still recommend using Thinking mode instead, but it's an improvement over GPT-5.3 Instant which we were stuck with until now. Especially good for Free tier users, who don't have other options!
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@sam_badawi
Sam Badawi
on x
OpenAI has made GPT-5.5 Instant the default ChatGPT model, significantly reducing hallucinations and improving accuracy across complex reasoning tasks. The update also brings more natural responses and deeper personalization, signaling continued progress toward reliable, [image]
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@mikelecheve
Mikel
on x
GPT-5.5 Instant isn't just an upgrade... it's a reliability jump ⚡ Better facts Stronger reasoning More trust in high-stakes domains Medicine. Law. Finance. + real gains in vision & STEM tasks This is what “production-ready AI” starts to look like Are we finally there? [image]
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@openai
@openai
on x
We're also improving memory and personalization. ChatGPT can now better use context from saved memories, past chats, files, and connected Gmail accounts to give more personalized responses. Memory sources show what relevant context was used to personalize a response and allow [vi…
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@openai
@openai
on x
GPT-5.5 Instant is more dependable, with significant improvements in factuality, especially in domains where accuracy matters most, like medicine, law, and finance. It's also stronger across everyday tasks, from analyzing image uploads to answering STEM questions to knowing when …
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@openai
@openai
on x
GPT-5.5 Instant is starting to roll out in ChatGPT. It's a big upgrade, giving you smarter, clearer, and more personalized answers in a warmer, more natural tone. And it's also more concise, which we heard you wanted. We think you'll love chatting with it. [video]
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@sama
Sam Altman
on x
5.5 instant comes to ChatGPT today! imo it is a pretty big upgrade, i really like using it.
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@christinahartw
Christina Wadsworth Kaplan
on x
New personalization updates in Chat for Plus and Pro are rolling out today! Chat can use more of your information to personalize and you can also see *how* Chat's using what it knows about you via memory sources. Let us know what you think and what you want to see next!