GPT-5.5 vs Claude 4 Opus for Summarisation
Compare GPT-5.5 by OpenAI and Claude 4 Opus by Anthropic for summarisation tasks - pricing, context windows, and strengths, and see how to put either to work in Appaca.
GPT-5.5
OpenAI's smartest and most capable model yet for agentic coding, knowledge work, and computer use, delivering a new class of intelligence at GPT-5.4 latency.
View GPT-5.5Claude 4 Opus
The flagship model, focused on deep reasoning, large-scale coding and sustained multi-step agentic workflows.
View Claude 4 OpusGPT-5.5 vs Claude 4 Opus at a glance
Specs and pricing side by side, from the Appaca AI models directory.
| Spec | GPT-5.5 | Claude 4 Opus |
|---|---|---|
| Provider | OpenAI | Anthropic |
| Model type | Text | Text |
| Context window | 1M tokens | 200K tokens |
| Input price | $5 / 1M tokens | $15 / 1M tokens |
| Output price | $30 / 1M tokens | $75 / 1M tokens |
| Status | Current | Superseded by Claude 4.1 Opus |
What matters for Summarisation
Evaluation criteria and how GPT-5.5 and Claude 4 Opus compare on what summarisation tasks actually require.
Accuracy and completeness of key information
Context window size for long document handling
Structured output formats (bullets, sections)
Reduction ratio without information loss
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GPT-5.5 is 67% cheaper on input tokens ($5 vs $15 per million), which adds up quickly on high-volume summarisation workloads.
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GPT-5.5 is 60% cheaper on output tokens ($30 vs $75 per million) - the bigger factor for summarisation tasks that generate long responses.
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GPT-5.5's 1M tokens context window is roughly 5x larger than Claude 4 Opus's 200K tokens, so it can handle bigger inputs in a single summarisation pass.
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Claude 4 Opus has been superseded by Claude 4.1 Opus - for new summarisation builds, consider the newer model first.
Strengths side by side
Where each model shines, according to benchmarks and provider positioning.
GPT-5.5
1. Strongest Agentic Coding Model
- State-of-the-art on Terminal-Bench 2.0 (82.7%), Expert-SWE (73.1%), and SWE-Bench Pro (58.6%), outperforming GPT-5.4 on complex coding tasks.
- Holds context across large systems, reasons through ambiguous failures, and carries changes through surrounding codebases with fewer tokens.
2. Higher Intelligence at GPT-5.4 Latency
- Co-designed, trained, and served on NVIDIA GB200/GB300 NVL72 systems to match GPT-5.4 per-token latency while performing at a significantly higher level.
- Uses fewer tokens to complete the same tasks, making it more efficient as well as more capable.
3. Powerful for Knowledge Work & Computer Use
- Scores 84.9% on GDPval (44 occupations) and 78.7% on OSWorld-Verified for autonomous computer operation.
- Excels at generating documents, spreadsheets, and reports; naturally moves across finding information, using tools, and checking output.
4. Scientific Research Co-Scientist
- Leading performance on GeneBench, BixBench, and FrontierMath; helped discover a new proof about Ramsey numbers verified in Lean.
- Strong enough to meaningfully accelerate progress at the frontiers of biomedical and mathematical research.
Claude 4 Opus
- Highest capability in the family: described as “our most powerful model yet” by Anthropic.
- Exceptional at long-running tasks requiring thousands of steps and sustained focus (e.g., continuous codebase work for hours).
- Excellent performance on benchmarks: e.g., SWE-bench 72.5 % and Terminal-bench 43.2 %.
- Designed for complex agentic workflows, deep reasoning, tool use, and large context windows.
- Placed under a higher safety classification (ASL-3) due to its frontier capability and risk profile.
Use GPT-5.5 or Claude 4 Opus - or both
Appaca is the AI workspace for operators. Build internal summarisation tools and AI co-workers powered by GPT-5.5 or Claude 4 Opus - connected to your real data and ready for your whole team. No code, no deployment.
Describe it, and it's built
Tell the Appaca agent the internal tool you need for summarisation and it builds a working app powered by GPT-5.5 or Claude 4 Opus. No code, no API keys, no deployment.
Switch models without rebuilding
Start on GPT-5.5, test the same tool on Claude 4 Opus, and keep whichever performs better for your summarisation workflow - the rest of your app stays exactly as it is.
Automated for the whole team
Schedule tools to run on autopilot - daily digests, weekly reports, real-time triggers - and share them with your whole team from one workspace.
Describe it, and it's built
Tell the Appaca agent what your team needs for summarisation and it builds a working app powered by GPT-5.5 or Claude 4 Opus - connected to the tools you already use.
Keep comparing for Summarisation
More side-by-side model comparisons for summarisation tasks.
FAQs
Gemini 2.5 Pro and Claude 4 Opus are the top summarisation LLMs in 2026. Gemini 2.5 Pro handles the longest documents thanks to its 1M token context window, making it ideal for lengthy reports, legal documents, and multi-chapter texts. Claude 4 Opus produces the highest-quality summaries for complex documents where nuance and accuracy matter most.
GPT-5.5 is generally cheaper: $5 input / $30 output per million tokens, versus $15 / $75 for Claude 4 Opus. Actual cost depends on how many tokens your summarisation workload reads and writes.
GPT-5.5 has the larger context window at 1M tokens, compared to 200K tokens for Claude 4 Opus. For summarisation tasks, a larger window means the model can consider more context at once without losing track.
Yes. Appaca is a no-code AI workspace: describe the internal tool your team needs for summarisation and the Appaca agent builds it as a working app powered by GPT-5.5, Claude 4 Opus, or any other model in the directory - with a built-in database, team access, and integrations. No API keys to wire up and nothing to deploy.
Build Summarisation tools with GPT-5.5 or Claude 4 Opus
Describe the summarisation tool your team needs and get a working app powered by the model you choose - with a built-in database, team access, and integrations. No code, no deployment.