University of Kwazulu-Natal

I Tested Opus 4 5 Early Here S Where It Can Save You Hours On Complex

Bonisiwe Shabane
-
i tested opus 4 5 early here s where it can save you hours on complex

Even during a week that has felt like one endless model release after another. But I’m not here to tell you this is a big deal because of benchmarks. I’m here to tell you something more useful: How Opus 4.5 actually performed vs. Gemini 3 and ChatGPT 5.1 on messy, real world tests. And I have to give credit where it’s due! My Substack chat came up with this test: specifically credit to reader Kyle C., who suggested a real-world test based on his tree business.

Specifically, he had photos of rough tallies for shipped and received trees, and there were discrepancies. He had tested Gemini vs. Opus 4.5 head-to-head with eye-opening results—I wanted to go farther. So I riffed on Kyle’s idea and came up with the great Christmas tree challenge of 2025: Follow ZDNET: Add us as a preferred source on Google. I've got to tell you: I've had fairly okay coding results with Claude's lower-end Sonnet AI model.

But for whatever reason, its high-end Opus model has never done well on my tests. Usually, you expect the super-duper coding model to code better than the cheap seats, but with Opus, not so much. Also: Google's Antigravity puts coding productivity before AI hype - and the result is astonishing Now, we're back with Opus 4.5. Anthropic, the company behind Claude claims, and I quote, "Our newest model, Claude Opus 4.5, is available today. It's intelligent, efficient, and the best model in the world for coding, agents, and computer use."

Claude Opus 4.5 excels in backend and complex tasks, achieving the top spot on agentic benchmarks, but its high cost and limitations in front-end development suggest a combined approach with Gemini 3 for optimal... (Please check the video description on YouTube for direct links and verify availability) Claude Opus 4.5 excels in backend and complex tasks, achieving the top spot on agentic benchmarks, but its high cost and limitations in front-end development suggest a combined approach with Gemini 3 for optimal... (Please check the video description on YouTube for direct links and verify availability) Transform this video into a visual whiteboard-style infographic with key concepts and takeaways. AI research organization METR has released new benchmark results for Claude Opus 4.5.

Anthropic's latest model achieved a 50 percent time horizon of roughly 4 hours and 49 minutes—the highest score ever recorded. The time horizon measures how long a task can be while still being solved by an AI model at a given success rate (in this case, 50 percent). The gap between difficulty levels is big. At the 80 percent success rate, the time horizon drops to just 27 minutes, about the same as older models, so Opus 4.5 mainly shines on longer tasks. The theoretical upper limit of over 20 hours is likely noise from limited test data, METR says. Like any benchmark, the METR test has its limits, most notably, it only covers 14 samples.

A detailed breakdown by Shashwat Goel of the weaknesses is here. As a THE DECODER subscriber, you get ad-free reading, our weekly AI newsletter, the exclusive "AI Radar" Frontier Report 6× per year, access to comments, and our complete archive. Our newest model, Claude Opus 4.5, is available today. It’s intelligent, efficient, and the best model in the world for coding, agents, and computer use. It’s also meaningfully better at everyday tasks like deep research and working with slides and spreadsheets. Opus 4.5 is a step forward in what AI systems can do, and a preview of larger changes to how work gets done.

Claude Opus 4.5 is state-of-the-art on tests of real-world software engineering: Opus 4.5 is available today on our apps, our API, and on all three major cloud platforms. If you’re a developer, simply use claude-opus-4-5-20251101 via the Claude API. Pricing is now $5/$25 per million tokens—making Opus-level capabilities accessible to even more users, teams, and enterprises. Alongside Opus, we’re releasing updates to the Claude Developer Platform, Claude Code, and our consumer apps. There are new tools for longer-running agents and new ways to use Claude in Excel, Chrome, and on desktop.

In the Claude apps, lengthy conversations no longer hit a wall. See our product-focused section below for details. As our Anthropic colleagues tested the model before release, we heard remarkably consistent feedback. Testers noted that Claude Opus 4.5 handles ambiguity and reasons about tradeoffs without hand-holding. They told us that, when pointed at a complex, multi-system bug, Opus 4.5 figures out the fix. They said that tasks that were near-impossible for Sonnet 4.5 just a few weeks ago are now within reach.

Overall, our testers told us that Opus 4.5 just “gets it.” Let me tell you about the Thursday afternoon that changed how I build SaaS products forever. I was knee-deep in debugging when my CTO’s Slack message lit up my screen: “Why are our AI costs up 22% this week?” That moment – coffee cold, cursor blinking – started my 72-hour... What I learned might save your startup thousands. I remember exactly where I was when I saw the numbers – hunched over my mechanical keyboard at 11:47 PM. Our usage dashboard showed 83,000 “requests” last month, but the billing breakdown revealed the truth: Opus 4.5 wasn’t counting simple requests.

It was charging us based on three hidden factors that nobody had explained clearly. After three Red Bulls and frustration-driven GitHub issue searches, I finally found the real pricing formula buried in Cursor’s API documentation. Let me save you the headache: The “2X requests” UI label? Complete marketing speak. In reality, our “quick” code completions were costing us 5X more than we’d budgeted because of output token creep.

Through $2,800 in painful trial-and-error, I learned to watch these like a hawk: After a long wait, Anthropic released its new model Claude Opus 4.5, a few days ago on November 24, 2025, this model joins the rest of the Claude 4.5 family, the new model comes... This release came only one week after Google launched its powerful new model, Google Gemini 3 Pro, and after OpenAI released GPT-5.1. This increases the competition between the three leading AI companies, Opus 4.5 is priced 66–67% lower than the earlier Opus 4.1, which is a major price drop for a top model from Anthropic. Anthropic released Claude Opus 4.1 on August 5, 2025. Just a few months later, on November 24, 2025, the company launched Opus 4.5.

This quick turnaround was part of a busy release schedule. Anthropic pushed out three major AI models in less than two months: Claude Sonnet 4.5 arrived on September 29, Claude Haiku 4.5 followed on October 15, and then Opus 4.5 closed out the trio... The new model became available across multiple platforms right away. Developers can access it through the Claude API using the model identifier claude-opus-4-5-20251101. Major cloud providers also jumped on board quickly Amazon Bedrock, Google Cloud Vertex AI, and Microsoft Azure all offer Opus 4.5 through their platforms. Microsoft moved especially fast.

The company made Opus 4.5 available in Azure Foundry and Copilot Studio on the same day as the public release. GitHub Copilot users with Enterprise or Pro+ subscriptions can now test Opus 4.5 in public preview mode. Meet Gemini 3 Pro, Google’s most powerful AI model yet — 1M-token context, deep reasoning and true AI agents that can plan, build and execute. GLM 4.7 vs MiniMax M2.1—open models that surprisingly rival Opus 4.5 vibes. We break down strengths, tradeoffs, and when to use each in production. Explore how GPT-5.1 boosts ChatGPT with better reasoning, warmer conversations, and improved control over tone, style, and workflow efficiency.

An updated METR graph including Claude Opus 4.5 was just published 3 hours ago on X by METR (source): Same graph but without the log (source): We estimate that, on our tasks, Claude Opus 4.5 has a 50%-time horizon of around 4 hrs 49 mins (95% confidence interval of 1 hr 49 mins to 20 hrs 25 mins). While we're still working through evaluations for other recent models, this is our highest published time horizon to date. We don’t think the high upper CI bound reflects Opus’s actual capabilities: our current task suite doesn’t have enough long tasks to confidently upper bound Opus 4.5’s 50%-time horizon. We are working on updating our task suite, and hope to share more details soon.

Based on our experience interacting with Opus 4.5, the model’s performance on specific tasks (including some not in our time horizon suite), and its benchmark performance, we would be surprised if further investigation showed...

People Also Search

Even During A Week That Has Felt Like One Endless

Even during a week that has felt like one endless model release after another. But I’m not here to tell you this is a big deal because of benchmarks. I’m here to tell you something more useful: How Opus 4.5 actually performed vs. Gemini 3 and ChatGPT 5.1 on messy, real world tests. And I have to give credit where it’s due! My Substack chat came up with this test: specifically credit to reader Kyle...

Specifically, He Had Photos Of Rough Tallies For Shipped And

Specifically, he had photos of rough tallies for shipped and received trees, and there were discrepancies. He had tested Gemini vs. Opus 4.5 head-to-head with eye-opening results—I wanted to go farther. So I riffed on Kyle’s idea and came up with the great Christmas tree challenge of 2025: Follow ZDNET: Add us as a preferred source on Google. I've got to tell you: I've had fairly okay coding resul...

But For Whatever Reason, Its High-end Opus Model Has Never

But for whatever reason, its high-end Opus model has never done well on my tests. Usually, you expect the super-duper coding model to code better than the cheap seats, but with Opus, not so much. Also: Google's Antigravity puts coding productivity before AI hype - and the result is astonishing Now, we're back with Opus 4.5. Anthropic, the company behind Claude claims, and I quote, "Our newest mode...

Claude Opus 4.5 Excels In Backend And Complex Tasks, Achieving

Claude Opus 4.5 excels in backend and complex tasks, achieving the top spot on agentic benchmarks, but its high cost and limitations in front-end development suggest a combined approach with Gemini 3 for optimal... (Please check the video description on YouTube for direct links and verify availability) Claude Opus 4.5 excels in backend and complex tasks, achieving the top spot on agentic benchmark...

Anthropic's Latest Model Achieved A 50 Percent Time Horizon Of

Anthropic's latest model achieved a 50 percent time horizon of roughly 4 hours and 49 minutes—the highest score ever recorded. The time horizon measures how long a task can be while still being solved by an AI model at a given success rate (in this case, 50 percent). The gap between difficulty levels is big. At the 80 percent success rate, the time horizon drops to just 27 minutes, about the same ...