Product Launch · XiaoHu Explains

OpenAI officially launches GPT-5.6: composite intelligence score closes in on Claude Fable 5, cost cut in half, ChatGPT and Codex merge

Three model tiers — Sol, Terra, Luna — plus a new ultra mode that runs 4 agents in parallel, all launched today. Same day: ChatGPT Work goes live and Codex merges into ChatGPT. Bilingual launch event video included.
TL;DR
  • OpenAI officially released the GPT-5.6 family of three model tiers: flagship Sol, balanced Terra, and value-priced Luna — rolling out today across ChatGPT, Codex, and the API, fully live worldwide within 24 hours.
  • The same day also brought ChatGPT Work (an agent with Codex built in that breaks tasks into steps and delivers finished output, positioned against Claude Cowork), plus the merger of the Codex app into a new ChatGPT desktop app — both powered by GPT-5.6.
  • A new ultra mode coordinates 4 agents working in parallel by default on complex tasks; on the API side, developers can build a similar experience via the Responses multi-agent beta.
  • Official benchmarks: Sol scored 80 on the Artificial Analysis Coding Agent Index, a new high. On the Intelligence Index, it comes within 1 point of Claude Fable 5 while using roughly half the cost and 61% less time.
  • Cybersecurity scores jumped sharply (ExploitBench rose from 47.9% to 73.5%); OpenAI says it still hasn't crossed the "Critical risk" threshold, and safeguard interception strength is up roughly 10x.
  • Pricing: Sol is $5 input / $30 output per million tokens, Terra $2.5/$15, Luna $1/$6 — with a new, more stable prompt caching mechanism.
Editorial note: this piece is compiled from OpenAI's official launch blog. All benchmark scores, costs, and timing figures are OpenAI's own self-reported numbers; some latency figures are offline-simulated estimates rather than measured results, the cybersecurity evaluations were run with safeguards lowered, and none of it has been independently reproduced by a third party.
▶ Full Launch Event · Bilingual (Chinese/English)
OpenAI's official GPT-5.6 and ChatGPT Work launch event, full recording (about 35 minutes, bilingual Chinese/English subtitles). Includes a ChatGPT Work hands-on demo, a walkthrough of Sol's training, and product demos. Click to play — nothing loads until you do. Source: OpenAI official launch event
1 The Launch

OpenAI ships another new model — this time three tiers at once

OpenAI officially released the GPT-5.6 family today (2026-07-09), comprising flagship Sol, balanced Terra, and value-priced Luna, alongside a new ultra mode that coordinates multiple agents working in parallel.

This time, the headline isn't "smarter" — it's "get the same work done using fewer tokens, less time, and lower cost." The number in each tier's name marks the generation; Sol, Terra, and Luna are capability tiers that can each be upgraded independently.
Why it matters: Sol scored 80 on the Artificial Analysis Coding Agent Index, a new high for that benchmark. The new ultra mode runs 4 agents in parallel by default, splitting up tasks. On the Intelligence Index, Sol is just 1 point behind Claude Fable 5, yet takes 61% less time and costs roughly half as much.

And this wasn't just a model launch. The same day, OpenAI also shipped ChatGPT Work and merged Codex into ChatGPT, with GPT-5.6 as the engine driving it. That product-line shift is just as significant as the model itself — more on it in Section 9 below.

Rollout: available starting today across ChatGPT, Codex, and the OpenAI API simultaneously, rolling out globally in stages and reaching full availability within 24 hours. The sections below walk through OpenAI's own benchmarks, one at a time, to pin down exactly where the "more efficient" claim comes from, and what ultra actually is.

2 Cost-Efficiency

Same intelligence, so how is it cheaper and faster

Judging whether a model is worth using isn't just about "how high the score is" — it's also "how much money and time it took to get that score." GPT-5.6's pitch is squarely about the second half: cut the time and cost for the same batch of tasks while barely moving the score.

OpenAI makes this case with two composite benchmarks. One is Agents' Last Exam (long-horizon agentic workflows spanning 55 professional domains), where Sol hits a new high of 53.6, 13.1 points ahead of Claude Fable 5; even at medium reasoning effort, it still beats Fable 5 by 11.4 points, at roughly a quarter of the cost. The smaller models save even more: Terra and Luna beat Fable 5 at roughly one-sixteenth the cost. The other is the Artificial Analysis Intelligence Index (a blended score across agentic tasks, coding, scientific reasoning, and general ability), where Sol at the max tier scores just 1 point below Fable 5, while finishing tasks 61% faster and at roughly half the cost.

Sc ore Cheaper · Faster Pricier · Slower (cost, time →) Top-left is better Luna · 51.2 Terra · 55 GPT-5.6 Sol · 58.9 61% less time · ~half the cost Claude Fable 5 · 59.9
Intelligence Index: the x-axis represents cost and time (further left is cheaper), the y-axis is score. Sol sits almost as high as Fable 5, but noticeably further left. Diagram shows directional trend; scores are OpenAI's official figures.
Just 1 point
On the Intelligence Index, Sol scores 58.9 vs. Claude Fable 5's 59.9
61% less
Sol's time to complete the same batch of tasks vs. Claude Fable 5
~Half
Sol's estimated cost, roughly half that of Claude Fable 5
~1/16
The cost Terra and Luna needed to match Fable 5 on Agents' Last Exam
3 Ultra Mode

Ultra mode: 4 AIs split the work, then merge results

GPT-5.6 lets you dial how much time and compute it's willing to spend thinking, from low, medium, high, xhigh, all the way to max. Above max sits a new tier: ultra. It's not "one model thinking longer" — it's 4 agents brought in by default, splitting the task up to work in parallel, then merging their results.

Core Innovation · #1

OpenAI compared "1 agent" versus "4 agents" across three benchmarks: BrowseComp (web-browsing tasks), SEC-Bench Pro (security proof-of-concept work), and Terminal-Bench 2.1 (command-line tasks). The conclusion: adding a few parallel agents gets you a higher score in less time. On BrowseComp, for example, a single agent needed the full 8 minutes to reach 90.84%, while 4 agents hit 92.18% in just 6.58 minutes.

Toggle the agent count below to watch this "score vs. time" curve shift toward the top-left (further left is faster, higher is more accurate):

90% 70% Time (minutes) · left is faster → Claude Mythos Preview 87.9%

Single-agent baseline: from low to max, the score climbs steadily from 69.04% to 90.84%, but the top score needs the full 7.99 minutes. The curve leans bottom-right overall.

ultra default: 4 agents running in parallel shift the curve up and to the left at every reasoning tier. At max, it hits 92.18% in 6.58 minutes — faster and more accurate than single-agent.

16 agents: pushes further toward the top-left. Low tier hits 86.41% in under a minute; high tier reaches 92.18% in 2.79 minutes, topping out near 93.4%.

For developers, the API side ships a matching multi-agent beta: a single request lets GPT-5.6 run multiple parallel sub-agents and merge their results, effectively letting you build your own ultra-style experience.

🔧
Who gets it: ultra rolls out by product and plan tier — it's not for everyone. In ChatGPT Work it's open to Pro and Enterprise users; in Codex, to Plus and above (not available to Free, Go, or ChatGPT Work's Plus/Business users). Turning it on works the same as picking max: in the model (Sol/Terra/Luna) and reasoning-effort settings, dial up past max to ultra. The API has no separate ultra toggle — you build the equivalent by running parallel sub-agents yourself via the Responses multi-agent beta.
"GPT-5.6 is one of the strongest models we've tested on CursorBench, with solid results in early evaluation. It's a step forward for developers on steerability, intelligence, and overall efficiency."Oskar Schulz, President, Cursor
4 Coding

How coding got stronger: a new high score, and cheaper too

Sol is OpenAI's strongest coding model to date. On the Artificial Analysis Coding Agent Index, it scores 80 at the max tier — a new high for the benchmark, 2.8 points ahead of Claude Fable 5 — while using less than half the output tokens, less than half the time, and roughly a third less cost. The whole family benefits: Terra edges out Fable 5, and Luna beats Opus 4.8, each using roughly a third of the time, about half the output tokens, and roughly a quarter of the cost.

80
Sol (max tier) hits a new high on the Coding Agent Index, 2.8 points ahead of Claude Fable 5
Less than half
The output tokens and time used to reach that score — both under half of Fable 5's
~1/3 lower
Estimated cost, roughly a third lower than Claude Fable 5
Two new highs
Also set new highs on Terminal-Bench 2.1 and DeepSWE, both real-codebase benchmarks

Where the savings come from: the model writes its own small program to handle tool calls

Coding and tool-heavy work used to work like this: every time the model called a tool, the tool's entire output got stuffed back into the conversation for the model to re-read before deciding the next step. More round trips meant more tokens burned. GPT-5.6 introduces Programmatic Tool Calling: the model writes a short program that coordinates multiple tools in memory, discards useless intermediate data, and only brings results back to itself at key checkpoints.

The old way: every step goes back through the model Model Tool Model Tool Model Every tool result gets stuffed back into the model whole — more round trips means more tokens burned. The new way: the model writes its own program and runs it in memory Model Model In-memory program Tool A Tool B Tool C Filter · keep only useful intermediate results The program itself keeps calling tools and filtering out useless data, bringing only the key conclusion back to the model once.
For the same tool-heavy task, the old way bounces back and forth through the model repeatedly; the new way tucks that whole process into a small in-memory program.
An Analogy

It's like sending an intern to run a checklist of errands on their own, only checking back in at key points — instead of calling in to ask permission before every single step. Fewer round trips means fewer tokens burned and less back-and-forth.

A side benefit: because intermediate data is handled in memory and never persisted, Programmatic Tool Calling naturally satisfies Zero Data Retention (ZDR — nothing is retained once processing is done), making it well-suited for data-sensitive industries like healthcare and finance connecting tool-heavy workflows.

5 Design

It can look at its own mockups, spot problems, and fix them

GPT-5.6 brings one notable change to interface design: give it a high-level direction, and it can produce interfaces that look good, feel right, and work — but more importantly, thanks to stronger computer-use ability, it can look at what it just rendered instead of just spitting out code, catching visual and functional issues and fixing them before handing the work back.

OpenAI's first example: from a single high-level instruction, GPT-5.6 built Saltwind, a playable sailboat-racing game — a fully playable 3D web game. Below is the game itself, embedded live — click "START REGATTA" to sail it yourself (A/D to steer, W/S to trim sail, spacebar to boost):

Saltwind: a playable 3D sailboat-racing game GPT-5.6 generated from a single sentence — read the wind, thread the gates, chase a faster line across a sunlit sea. The live game above can be sailed directly. If it fails to load due to network issues, you can play it here or in the original post. Source: OpenAI official blog

The other thread is turning a single sentence into an interactive explainer page. In ChatGPT Work, OpenAI gave three examples: an interactive spirograph, wave interference, and a GPT tokenizer visualization — all web pages that recompute live as you drag a slider. Take the spirograph first: the user just said "make an interactive spirograph to explain how it works," and after 1 minute 12 seconds of thinking, the model produced the page below directly (recorded run):

A recorded run of GPT-5.6's interactive spirograph: drag the four sliders on the right (fixed ring radius / rolling circle radius / pen offset / animation speed), and the curve on the left redraws live, labeled with how many turns the current parameters need to close the loop. Source: OpenAI official blog
The spirograph parametric equations the model wrote into the page itself
x = (R − r)·cos(t) + d·cos(((R − r)/r)·t)
y = (R − r)·sin(t) − d·sin(((R − r)/r)·t)
6 Template Reproduction

Copying a PPT template — whose copy is more faithful

GPT-5.6 can infer a full design spec from a reference document — layout, fonts, spacing, color, recurring content patterns, including rules buried in the Slide Master — and then apply those conventions consistently to new content. OpenAI shared a comparison of "update the numbers to match the reference": on the same reference template, GPT-5.5 missed key elements in the master slide, while GPT-5.6 followed the reference structure more completely.

Reference template slide
① Reference template: the model was asked to update the numbers while matching its layout and master-slide elements. Source: OpenAI official blog
GPT-5.5 output slide
② GPT-5.5 output: missed key elements in the master slide. Source: OpenAI official blog
GPT-5.6 output slide
③ GPT-5.6 output: followed the reference structure more completely. Source: OpenAI official blog

The same improvement shows up in documents and spreadsheets too: more faithfully following complex reference formats, more precise handling of formulas and financial models, and better use of layout, spacing, hierarchy, and page structure. That has a direct impact on knowledge work that requires repeatedly matching an existing format.

"GPT-5.6 is highly effective at the long, complex processes behind building production-grade applications. As one of the models Lovable now uses, it's helped users complete the same tasks with roughly 25% fewer steps and 35-48% fewer tool calls, while improving project success rates and cutting stuck runs by 15%."Fabian Hedin, Co-founder, Lovable
7 Cybersecurity

Cybersecurity capability jumped a tier — how OpenAI is gating it

GPT-5.6 is OpenAI's strongest cybersecurity model to date, and it uses fewer tokens doing it. The jump across three benchmarks is stark: ExploitBench (measuring progress from touching vulnerable code to achieving arbitrary code execution) rose from GPT-5.5's 47.9% to 73.5%; ExploitGym (turning real vulnerabilities into working exploits) climbed from 15.1% to 24.9% within a two-hour cap, reaching 33.7% when relaxed to six hours; SEC-Bench Pro (proof-of-concept generation on complex software) rose from 45.8% to 71.2%.

ExploitBench · GPT-5.5
47.9%
ExploitBench · GPT-5.6
73.5%
SEC-Bench Pro · GPT-5.5
45.8%
SEC-Bench Pro · GPT-5.6
71.2%
ExploitGym · GPT-5.5
15.1%
ExploitGym · GPT-5.6
24.9%

OpenAI's safety verdict on this capability: GPT-5.6 is stronger than prior models in both biological and cyber risk, but neither has crossed the "Critical" risk threshold. In cybersecurity specifically, OpenAI's testing suggests it's better at "finding and fixing vulnerabilities" than at reliably mounting end-to-end autonomous attacks against a hardened target, leaving defenders a window to shore up their systems first. Defensive tasks (secure code review, patching, threat modeling, blue-team exercises) remain the priority direction it supports.

The safeguards are layered: protections trained into the model itself, plus real-time checks, ongoing monitoring, and account-level controls. OpenAI also added a "reasoning monitor" that reviews an entire conversation for potential harm, rather than relying solely on flags from a lower-capability classifier to decide whether to block. Compared with before, Sol's cybersecurity safeguards block potentially harmful behavior at roughly 10x the previous strength; for legitimate use that gets wrongly blocked, ChatGPT and Codex offer a one-click option to retry with a lower-capability model. Before launch, OpenAI ran roughly 700,000 A100e-GPU-hours of black-box automated red-teaming.

~10x
Sol's cybersecurity safeguards block potentially harmful behavior at roughly 10x the strength of prior models
Sept 1
Individual users must enable hardware-key two-factor authentication by September 1, 2026, or lose access to the strongest cybersecurity model and drop back to the default tier
What is Trusted Access for Cyber

This is an elevated-access program from OpenAI Daybreak, open to verified security researchers and institutions. Verified users can unlock stronger defensive capabilities in authorized environments — things like vulnerability classification and validation, malware analysis, detection engineering, and patch validation; unverified users don't get this tier of access. The most sensitive capabilities are reserved for these trusted users, to balance "enabling legitimate defensive work" against "blocking serious misuse."

8 Full Benchmark Table

The full scorecard: where it beats Claude, where it doesn't yet

The charts OpenAI chose to highlight are, naturally, the ones where it's ahead. Laying out the full benchmark table from the appendix gives a more complete picture: GPT-5.6 Sol has categories where it leads by a wide margin, and categories where Claude Mythos 5 pulls ahead. Below are a few key comparisons by category.

Benchmark (category)GPT-5.6 SolBest rival scoreLeader
ARC-AGI-3
(abstract reasoning)
7.78%1.5%
Claude Opus 4.8
GPT, by a wide margin
OSWorld 2.0
(computer use)
62.6%54.8%
Claude Opus 4.8
GPT leads
Coding Agent Index
(Coding Agent)
8077.2
Claude Fable 5
GPT leads
BrowseComp
(web browsing, Sol Ultra)
92.2%88%
Claude Mythos 5
GPT leads
SWE-Bench Pro
(real codebases)
64.6%80.3%
Claude Mythos 5
Claude leads
FrontierMath Tier 4
(hard math)
83%87.8%
Claude Mythos 5
Claude leads
Intelligence Index
(Intelligence Index)
58.959.9
Claude Fable 5
Claude leads narrowly
Toolathlon
(tool use)
58%61.7%
Claude Mythos 5
Claude leads
Over 5x
On ARC-AGI-3 abstract reasoning, Sol scores 7.78% — more than 5 times the runner-up, Claude Opus 4.8 (1.5%). Note: Opus 4.8's score there was run at the high tier, not max, so this isn't a same-tier comparison.
Show more categories (academic, multimodal, long-context, etc.)
BenchmarkSolTerraGPT-5.5Best Claude
GPQA Diamond94.6%92.9%93.6%94.6% (Mythos Prev.)
FrontierMath Tier 1-389%84.9%85.3%87% (Fable 5)
MMMU Pro (with tools)84.6%82%83.2%
GraphWalks BFS 1M77.1%71.2%45.4%79.4% (Mythos 5)
GDPval-AA v2 (Elo)1747.815931493.71759.6 (Fable 5)
Terminal-Bench 2.188.8%87.4%85.6%88% (Mythos 5)
BenchCAD (python)83.4%78.2%55.8%65% (Mythos 5)

Footnote: HealthBench Professional uses OpenAI's own paper scoring methodology, which differs from Anthropic's system-card methodology — the two numbers shouldn't be compared at face value. In multi-agent (ultra) evaluations, latency is counted for the primary agent only, while tokens and cost are summed across all sub-agents.

9 Product Changes

Not just a new model: Codex merges into ChatGPT, plus a new ChatGPT Work that does the work itself

The same day as GPT-5.6, OpenAI also reshaped its product lineup: it launched ChatGPT Work and merged the standalone Codex app into ChatGPT, with GPT-5.6 as the engine driving it. This half of the announcement is just as significant as the model itself.

What ChatGPT Work is: a ChatGPT agent with Codex built in, able to pull context from your various apps, break a goal down into steps, and hand back a finished spreadsheet, slide deck, document, or web page directly — not advice, a finished product. It can schedule work and run multi-step tasks in the background on its own (positioned against Anthropic's Claude Cowork), can use your local files and apps, and can also use a new built-in browser to reach websites and online files; it connects into various systems via Plugins; and there's a new experimental Sites feature — drag in a folder or a zip and it instantly becomes a running website.

The desktop merger: the previously standalone Codex app has merged into a new ChatGPT desktop app (available on both Mac and Windows), with Chat, Work, and Codex all available in every plan, including the free tier. Users who already have the Codex app just need to update to get the new ChatGPT desktop app; the previous standalone ChatGPT desktop app has been renamed ChatGPT Classic.

Old Codex app
+
ChatGPT app
New ChatGPT desktop app
Chat · Work · Codex, all-in-one

All-in-one on desktop, available on every plan (including free); the old standalone version is now ChatGPT Classic.

🧭
This move didn't come out of nowhere. Back on 2026-05-16, OpenAI had already merged the consumer ChatGPT team and the Codex team into a single core product group, put under President and co-founder Greg Brockman. The merger was both a product decision and a compute decision — Brockman has said compute is the hard constraint — and it's also been read externally as pre-IPO simplification: folding three product lines with different economics (consumer, developer, research) into a single, cleaner story. Today's ChatGPT Work launch plus Codex merger is that team merger landing in the product.

Availability: ChatGPT Work launches today for Pro, Enterprise, and Edu plans, expanding to Plus and Business in the coming days.

10 Availability & Pricing

When you can use it, and what it costs

GPT-5.6 is live today across ChatGPT, Codex, and the OpenAI API, rolling out globally in stages and reaching full availability within the next 24 hours. Of the three tiers, Sol is the flagship, Terra is a lower-cost tier with performance close to GPT-5.5, and Luna is the fastest and cheapest.

Free / Go
Uses Terra
Plus and above
Choice of all three tiers, each with its own effort setting
Pro / Enterprise
Can select Sol Pro, ultra

Breakdown: in ChatGPT, Plus, Pro, Business, and Enterprise users get Sol at medium effort and above, and Pro/Enterprise can also select Sol Pro. In ChatGPT Work and Codex, Free and Go use Terra, while Plus and above can choose between Sol, Terra, and Luna and set their own effort tier; the max tier is available in settings to every user who has access to GPT-5.6 at all. ultra is available in ChatGPT Work to Pro and Enterprise, and in Codex to Plus and above.

Pricing (per million tokens)

$5 / $30
Sol: $5 input, $30 output
$2.5 / $15
Terra: $2.5 input, $15 output
$1 / $6
Luna: $1 input, $6 output
30 minutes
New prompt caching mechanism: supports explicit cache breakpoints, with a minimum cache lifetime of 30 minutes

Cache pricing has also changed: starting with GPT-5.6, writing to the cache costs 1.25x the uncached input price, while reading from the cache still gets a 90% discount. For applications that repeatedly send the same long context, caching is now more predictable and easier to budget for.

Further Reading

Want to go deeper

First, a few real screenshots. Derrick Choi, an OpenAI Codex engineer, brainstormed entirely by voice with Codex, then had GPT-5.6 Sol generate whole pages single-shot, producing 15 working websites/UIs. Below are 4 of them:

Community Test · All 15
Derrick Choi's 15 single-shot GPT-5.6 Sol case studies
Beyond the 4 above, there's an interactive Pokémon comic log, a scroll-driven 3D product-shot camera, a fictional Michelin restaurant, a playable browser synthesizer, an interactive black hole, a Dolomites hotel, an ink-and-marble studio, and more. Each comes with a demo video. It's independent evidence beyond the vendor's own official demos.
See all 15 case studies on X →
On-Site Explainer · The Other Half
OpenAI launches ChatGPT Work, powered by GPT-5.6, auto-producing docs, spreadsheets, and slides across tools
The product line that launched the same day, powered by the same model. Section 9 above gives the gist — this piece is the full explainer.
Read the ChatGPT Work explainer →
Original Source
GPT-5.6: Frontier intelligence that scales with your ambition
OpenAI's official launch blog post itself, with all original charts, the full benchmark appendix, and the methodology footnotes cited in this piece.
Read the official post →
This piece is compiled from OpenAI's official launch blog post "GPT-5.6: Frontier intelligence that scales with your ambition" (2026-07-09). All benchmark scores, costs, and timing figures in this piece are OpenAI's own self-reported numbers; some latency figures are offline-simulated estimates, the cybersecurity evaluations were run with safeguards lowered, and none of it has been independently reproduced by a third party. · XiaoHu · AI Explainer Site