Published: November 15, 2025
A new default for AI work: GPT‑5.1 rolls out across the stack
OpenAI’s newest flagship model, GPT‑5.1, is moving from announcement to reality across the developer ecosystem. In just a few days it has:
- Launched in the OpenAI API with new tools and a revamped reasoning system. [1]
- Rolled out in GitHub Copilot as GPT‑5.1, GPT‑5.1‑Codex and GPT‑5.1‑Codex‑Mini. [2]
- Become available as an experimental model in Microsoft Copilot Studio, powering low‑code agentic workflows. [3]
- Started upgrading ChatGPT itself to GPT‑5.1 Instant and GPT‑5.1 Thinking, with new tone and personalization controls. [4]
Around those core launches, today’s news cycle (15 November 2025) is full of ripple effects: OpenAI is piloting group chats powered by GPT‑5.1, Perplexity AI has integrated the model for its paid users, and coverage from India to Kuwait is framing GPT‑5.1 as a step toward more human‑centric, localized AI. [5]
Here’s a breakdown of what’s new, why it matters, and how to start using GPT‑5.1 today.
What GPT‑5.1 actually is (in one paragraph)
OpenAI describes GPT‑5.1 as the next model in the GPT‑5 series, built to balance “frontier” intelligence with much lower latency and better control over how long the model thinks. On easy questions, it spends fewer tokens thinking and responds faster; on hard problems, it leans into deeper reasoning instead of cutting off early. [6]
In practice, that translates into quicker answers for everyday tasks, more reliable behavior on complex ones, and a lot more dials developers can turn.
GPT‑5.1 for developers: adaptive reasoning, “no reasoning” mode and new tools
OpenAI’s “Introducing GPT‑5.1 for developers” post is the technical heart of this release. [7]
Adaptive reasoning instead of one‑size‑fits‑all
GPT‑5.1 introduces adaptive reasoning: the model dynamically adjusts how much “thinking” it does per request.
- On straightforward prompts (e.g., a simple CLI command), GPT‑5.1 can answer in roughly a fifth of the tokens GPT‑5 used, resulting in much lower latency and cost. [8]
- On difficult, tool‑heavy tasks, it remains persistent, exploring alternatives and checking its own work rather than truncating reasoning early. [9]
External testers are already reporting real‑world gains:
- Balyasny Asset Management saw GPT‑5.1 run 2–3× faster than GPT‑5, while using roughly half the tokens of competing models at similar or better quality on their eval suite. [10]
- Pace, an AI insurance BPO, says its agents run about 50% faster on GPT‑5.1 while improving accuracy over GPT‑5 and other leading models. [11]
- A commentary summarized by StartupHub.ai cites Box benchmarks where time‑to‑first‑token dropped by more than 80% on some enterprise document tasks. [12]
New reasoning_effort controls and “no reasoning” mode
Developers now get an explicit reasoning_effort knob with four levels: none, low, medium, and high. [13]
noneturns GPT‑5.1 into a non‑reasoning model for latency‑sensitive workloads, but keeps its higher intelligence and stronger tool‑calling. This is now the default.- OpenAI recommends
lowormediumfor most complex tasks, andhighwhen intelligence and reliability matter more than speed. [14] - Startup Sierra reports roughly a 20% improvement in low‑latency tool‑calling when using GPT‑5.1 in “no reasoning” mode compared with GPT‑5’s minimal reasoning. [15]
For teams who’ve struggled with models spending too long “thinking” on simple tasks, this is a big operational win.
Extended prompt caching for 24 hours
GPT‑5.1 also extends prompt cache retention to 24 hours (up from just a few minutes), while keeping cached input tokens at a 90% discount compared with normal input tokens. [16]
That’s especially useful if you:
- Keep a long‑running chat or coding session open all day
- Reuse the same system prompt across many follow‑ups
- Run agentic workflows that repeatedly reference the same context
You can enable this behavior by setting a prompt_cache_retention parameter (e.g., '24h') on the Responses or Chat Completions API.
New tools: apply_patch and shell
GPT‑5.1 ships with two new tools designed for agentic workflows: [17]
apply_patchtool- Lets the model express code changes as structured patches instead of free‑form text.
- Improves reliability on multi‑file edits and code review workflows (OpenAI’s SWE‑bench Verified score climbs over 76% with GPT‑5.1 at high reasoning). [18]
- Shell tool
- Enables a plan‑execute loop where the model proposes shell commands, your integration runs them locally or in a sandbox, and the command outputs flow back into the model. [19]
- Ideal for tasks like scaffolding projects, running tests, inspecting file systems, or collecting diagnostics.
OpenAI’s own guidance is to wire these tools through the Responses API using tools: [{ "type": "shell" }, { "type": "apply_patch" }], then handle the shell_call and patch instructions on your side. [20]
Pricing and model SKUs
On the API side, GPT‑5.1 comes in several flavors: [21]
gpt-5.1– the main high‑reasoning modelgpt-5.1-chat-latest– Chat‑style Instant modelgpt-5.1-codexandgpt-5.1-codex-mini– specialized coding variants optimized for long‑running, agentic coding in Codex‑like environments
Crucially, pricing and rate limits are the same as GPT‑5, easing migration. OpenAI also says GPT‑5 remains available for now and any deprecation will come with advance notice. [22]
GPT‑5.1 lands in GitHub Copilot: more intelligence directly in your IDE
GitHub has pushed the full GPT‑5.1 series into public preview for GitHub Copilot. [23]
Where you can use GPT‑5.1 inside Copilot
According to the GitHub Changelog, GPT‑5.1 models are available to Copilot Pro, Pro+, Business and Enterprisesubscribers, with coverage across tools developers actually use day‑to‑day: [24]
- GPT‑5.1 (general model)
- Visual Studio Code: chat, ask, edit, agent
- JetBrains IDEs: ask, edit, agent
- Xcode: ask, agent
- Eclipse: ask, agent
- GitHub.com
- GitHub Mobile (iOS, Android)
- Copilot CLI
- GPT‑5.1‑Codex and GPT‑5.1‑Codex‑Mini
- VS Code (1.104.1+) in all modes
- GitHub Copilot for JetBrains (1.5.61+)
- Copilot for Xcode (0.45.0+) and Eclipse (0.13.0+) in ask/agent modes
- Copilot CLI
Rollout is gradual, so not every organization sees all 5.1 models immediately.
How to turn it on
GitHub breaks down enablement this way: [25]
- Enterprise / Business: admins must explicitly enable the GPT‑5.1 policies in Copilot settings, after which users can pick the models in the Copilot Chat model picker.
- Pro / Pro+: users can simply select GPT‑5.1 or GPT‑5.1‑Codex from the picker and confirm the one‑time prompt.
- Bring your own OpenAI key: choose GPT‑5.1 or GPT‑5.1‑Codex variants in “Manage Models” and supply an API key.
For many teams, this means agentic coding, code review and inline edits are now backed by GPT‑5.1 without changing existing Copilot workflows.
GPT‑5.1 in Microsoft Copilot Studio: experimental engine for enterprise agents
On the Microsoft side, GPT‑5.1 has arrived as an experimental model in Copilot Studio, the company’s low‑code environment for building enterprise AI agents. [26]
Key points from Microsoft’s Copilot blog:
- GPT‑5.1 is available today to certain U.S. customers in early‑release Power Platform environments. [27]
- It appears as GPT‑5.1 Chat and GPT‑5.1 Reasoning options when configuring agents, mirroring the Instant/Thinking split. [28]
- Microsoft explicitly labels these as experimental and recommends non‑production usage while they complete internal evaluation gates. [29]
The idea is to let enterprises:
- Prototype long‑running, agentic processes (e.g., customer support flows, back‑office automations) with GPT‑5.1’s adaptive reasoning.
- Benchmark GPT‑5.1 against existing models in Copilot Studio before moving anything into production.
For organizations already standardizing on Microsoft 365 and Power Platform, this is the most direct on‑ramp to GPT‑5.1‑powered internal agents.
GPT‑5.1 in ChatGPT: Instant vs Thinking, new tone controls and more “personality”
While the developer and platform integrations matter, GPT‑5.1 is also changing how ChatGPT itself behaves.
Instant vs Thinking in ChatGPT
OpenAI’s GPT‑5.1 product blog and the official release notes describe two main variants: [30]
- GPT‑5.1 Instant
- The default everyday model, now warmer and more conversational.
- Uses light adaptive reasoning for harder questions while staying fast.
- Shows big gains on math and coding benchmarks without feeling stiff or overly formal.
- GPT‑5.1 Thinking
- The upgraded deep‑reasoning model.
- Adapts its thinking time more precisely to task complexity—shorter for simple tasks, longer for truly hard problems.
- Produces clearer explanations with less jargon, making advanced reasoning more approachable for non‑experts.
GPT‑5.1 Auto continues to route each query to the most suitable model, while GPT‑5 stays accessible for about three months under a “Legacy models” dropdown so users can compare behavior. [31]
Rollout order:
- Paid users (Pro, Plus, Go, Business)
- Free and logged‑out users
- Enterprise and Edu, with a temporary early‑access toggle before GPT‑5.1 becomes the new default. [32]
New tone presets and personality system
The most visible change for everyday users is tone control. OpenAI has expanded and renamed ChatGPT’s personalities, with both the release notes and third‑party coverage highlighting the new presets. [33]
You can now toggle among options like:
- Default
- Friendly
- Efficient
- Professional
- Candid
- Quirky
- Nerdy
- Cynical
OpenAI is also experimenting with sliders for conciseness, warmth, “scannability” and emoji frequency, and these preferences apply across all chats immediately, including existing conversations. [34]
The Verge and The Register both emphasize that GPT‑5.1 is intentionally “warmer” with more personality options, giving users more control over how human or neutral the assistant sounds, while OpenAI stresses it’s still working to avoid sycophantic behavior. [35]
Better instruction following—even for punctuation quirks
One surprisingly popular story in today’s coverage: ChatGPT finally respects instructions not to use em dashes, a long‑standing irritation for writers who could spot AI‑generated text by its punctuation style. [36]
According to WebProNews’s piece on Sam Altman’s “dash dilemma,” the fix is part of broader improvements in instruction following and custom style adherence—likely powered by the same GPT‑5.1 updates that underpin the new tone controls. [37]
Fresh for November 15: group chats, Perplexity integration and India‑focused IndQA
Beyond the official launch posts, today’s news cycle around GPT‑5.1 features several notable developments.
1. Group chats in ChatGPT, powered by GPT‑5.1
OpenAI has begun piloting group chats, where multiple people and ChatGPT share the same conversation thread. [38]
Key details:
- The feature is rolling out on ChatGPT web, iOS and Android in New Zealand, Japan, South Korea and Taiwanfirst. [39]
- GPT‑5.1 lets ChatGPT watch the conversation and decide when to speak up, instead of responding to every single message. Times Kuwait calls this out as a major change in how chatbots are used: the bot becomes more of a participant than a constant narrator. [40]
For teams, classrooms or friends planning trips together, this is the closest ChatGPT has come to feeling like another person in the group thread rather than a separate one‑on‑one chat.
2. Perplexity AI integrates GPT‑5.1 for Pro and Max users
Perplexity AI, a competing AI search engine, has already integrated GPT‑5.1 for its paid tiers. [41]
According to The Financial Express:
- GPT‑5.1 models are now available to Perplexity Pro ($20/month) and Max ($40/month) subscribers.
- CEO Aravind Srinivas confirmed the rollout on X, framing it as a move toward more natural, personalized conversations and sharper reasoning.
- For Perplexity’s 10M+ monthly users, GPT‑5.1 should make answers more dynamic and context‑aware, which is particularly appealing for research and professional workflows. [42]
The article also reiterates the Instant vs Thinking split, noting that Instant is the fast, conversational choice while Thinking is reserved for complex reasoning tasks—mirroring how OpenAI is positioning the models in ChatGPT and the API. [43]
3. GPT‑5.1 and IndQA: OpenAI’s India‑focused push
A piece in Forbes India ties GPT‑5.1 to a broader OpenAI strategy around localization via IndQA, a benchmark for assessing AI systems on Indian languages and cultural context. [44]
Highlights:
- GPT‑5.1 is framed as OpenAI’s most advanced model yet, with Instant and Thinking modes aimed at a mix of conversational and high‑reasoning tasks. [45]
- IndQA is designed to measure how well AI systems handle Indian languages and cultural nuance, with India serving as both a growth market and a testbed for localization strategies. [46]
Taken together, these moves signal that OpenAI wants GPT‑5.1 to be more than an English‑first, Western‑centric model—and that future iterations may be evaluated just as much on cultural competence as on raw benchmarks.
4. Coverage on tone, criticism of GPT‑5 and why 5.1 exists
Several outlets are framing GPT‑5.1 as a course‑correction from GPT‑5:
- Techzine notes that GPT‑5.1 aims to address criticisms of GPT‑5 by focusing on more natural language behavior, better instruction adherence and more user control, with OpenAI planning future updates as incremental iterations within the same generation. [47]
- Hindustan Times and Times of India both emphasize smarter conversations, faster responses, and expanded customization options—particularly the Instant/Thinking split and new tone presets. [48]
And multiple commentaries, including StartupHub.ai’s and The Verge’s coverage, describe GPT‑5.1 as a move back toward the conversational charm of GPT‑4‑era models, but with GPT‑5‑level intelligence and better enterprise features. [49]
What this means for developers and teams
From a practical standpoint, 15 November 2025 is the moment GPT‑5.1 stops being just another model number and becomes baked into the tools developers already use.
Here’s what to take away:
- For API developers
- You can swap GPT‑5 to GPT‑5.1 without a pricing surprise, then experiment with
reasoning_effortlevels to tune your latency vs. quality trade‑off. [50] - Use extended prompt caching plus
apply_patchand the shell tool to build more capable, long‑running agents that actually interact with your environment. [51]
- You can swap GPT‑5 to GPT‑5.1 without a pricing surprise, then experiment with
- For teams using GitHub Copilot
- GPT‑5.1 and its Codex variants are rolling out directly in your IDE, across chat, inline edits, and agent modes. Turn them on via the model picker or organization policies and watch how they handle multi‑file refactors, PR reviews and legacy codebases. [52]
- For organizations on Microsoft Copilot and Power Platform
- GPT‑5.1 is now an experimental engine for Copilot Studio agents, ideal for pilots and internal proofs of concept before production hardening. [53]
- For content teams, support leaders and knowledge workers
- GPT‑5.1 Instant plus the new tone presets finally give you a realistic shot at locking ChatGPT into a house style—professional, friendly, quirky, or even intentionally cynical—without constantly re‑prompting. [54]
- For the broader ecosystem
- Perplexity’s rapid integration and OpenAI’s own group‑chat experiments show GPT‑5.1 is quickly becoming the default brain behind next‑generation chat and search tools, not just a model you call from a single API endpoint. [55]
How to get access today
If you want to start using GPT‑5.1 right now, here’s the short version:
- OpenAI API
- Use
gpt-5.1orgpt-5.1-chat-latestin the Responses or Chat Completions APIs. - Add
reasoning_effort,prompt_cache_retention, and tools (apply_patch,shell) as needed. [56]
- Use
- GitHub Copilot
- On Pro/Pro+: pick GPT‑5.1 or GPT‑5.1‑Codex from the model picker.
- On Business/Enterprise: ask your admin to enable the new OpenAI GPT‑5.1 policies. [57]
- Microsoft Copilot Studio
- If you’re in a U.S. early‑release Power Platform environment, choose GPT‑5.1 Chat or GPT‑5.1 Reasoning when configuring agents, and keep usage to non‑production while Microsoft’s evaluation is ongoing. [58]
- ChatGPT (consumer and business plans)
- As rollout continues, look for GPT‑5.1 Instant and GPT‑5.1 Thinking in the model picker, then customize tone under Settings → Personalization. [59]
As of November 15, 2025, the story of GPT‑5.1 is no longer just about a smarter model on a benchmark chart. It’s about a single generation of AI that now spans ChatGPT, the OpenAI API, GitHub Copilot, Microsoft Copilot Studio, Perplexity and more—and that gives developers and organizations far more control over how much the model thinks, how fast it answers, and how human it sounds.
References
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