How strong is GPT-5.5? Public benchmarks show its power — and its limits

Still, the caveats matter. On SWE-Bench Pro, a benchmark focused on resolving GitHub issues, Claude Opus 4.7 scores higher than GPT-5.5. On BrowseComp, Gemini 3.1 Pro and Mythos Preview both score above GPT-5.5. So the fairest assessment is not that GPT-5.5 is the best model for every possible job. It is that GPT-5.5 is a very strong first candidate — and one that still needs to be compared against rivals for specific workflows.

What the main benchmarks say

The pattern is clear: GPT-5.5 looks especially compelling for terminal work, math-heavy reasoning, office tasks and general knowledge work. But for GitHub issue resolution, browsing-heavy research and some computer-use tasks, the competitive field is still close.

Where GPT-5.5 looks strongest

Coding and debugging

Development work is one of GPT-5.5’s clearest strengths. OpenAI says the model excels at writing and debugging code, and the Terminal-Bench 2.0 score of 82.7 backs up the idea that it is strong in command-line workflows.

That does not mean it is automatically the best model for every software engineering task. SWE-Bench Pro tells a more mixed story: GPT-5.5 scores 58.6, while Claude Opus 4.7 scores 64.3. If your work is mostly about fixing issues inside an existing repository, Claude deserves a side-by-side test.

Research, data analysis and multi-step work

OpenAI describes GPT-5.5 as capable of taking on messy, multi-part tasks: planning the work, using tools, checking its output, navigating ambiguity and continuing without close step-by-step management. That matters for research and analysis, where the hard part is often not a single answer but the chain of actions required to get there.

Even here, the benchmark picture is not one-sided. BrowseComp places GPT-5.5 at 84.4, below Gemini 3.1 Pro at 85.9 and Mythos Preview at 86.9. For search-heavy or browser-heavy workflows, GPT-5.5 may still be excellent — but it should be compared directly with those competitors.

Documents, spreadsheets and office work

GPT-5.5 also looks well suited to the less glamorous but highly valuable work of creating documents, manipulating spreadsheets, preparing reports and operating software. OpenAI lists documents, spreadsheets and software operation among the model’s strengths, and The New York Times reported that OpenAI said the new technology was better at writing code and tasks related to office work.

The benchmark support is meaningful: GPT-5.5 scores 54.1 on OfficeQA Pro, ahead of Claude Opus 4.7 at 43.6 and Gemini 3.1 Pro at 18.1. For teams using AI to draft internal documents, work through spreadsheets, build procedures or support office workflows, this is one of GPT-5.5’s most relevant advantages.

Math and technical reasoning

GPT-5.5 also performs strongly on FrontierMath. In the cited comparison, it scores 51.7 on Tier 1–3 and 35.4 on Tier 4, above Claude Opus 4.7 and Gemini 3.1 Pro on the same rows. That makes it a serious option for tasks involving quantitative reasoning, technical analysis or structured problem-solving.

How much of a jump is it from GPT-5.4?

GPT-5.4 was described by OpenAI as a model that combined advances in reasoning, coding and agentic workflows, with improvements across tools, software environments and professional work involving spreadsheets, presentations and documents.

GPT-5.5 appears to push that same direction further: less hand-holding, more autonomous task execution. OpenAI says GPT-5.5 can understand what users are trying to do faster and carry more of the work itself. OpenAI also says GPT-5.5 shows a clear improvement over GPT-5.4 on GeneBench, an evaluation focused on multi-stage scientific tasks.

Is GPT-5.5 stronger than Claude or Gemini?

It depends on the job.

On Terminal-Bench 2.0, FrontierMath, OfficeQA Pro and GDPval, GPT-5.5 beats the Claude Opus 4.7 and Gemini 3.1 Pro results shown in the public comparison tables. That makes it a natural first choice for terminal workflows, math-heavy reasoning, office tasks and many knowledge-work scenarios.

But Claude Opus 4.7 leads GPT-5.5 on SWE-Bench Pro, and Gemini 3.1 Pro leads GPT-5.5 on BrowseComp. Mythos Preview also leads GPT-5.5 on BrowseComp and OSWorld-Verified. In plain English: GPT-5.5 is one of the strongest models available, but the best model still depends on the task.

How to judge it for real work

Benchmarks are useful signals, but they are not a substitute for testing against your own workload. If you are choosing a model for a team or product, the right question is not simply which leaderboard it tops. It is whether the model performs reliably on your actual prompts, files, repositories, tools and review standards.

A practical evaluation might look like this:

• For existing-codebase issue resolution, include Claude Opus 4.7 in the comparison because it scores higher than GPT-5.5 on SWE-Bench Pro.
• For command-line development workflows, treat GPT-5.5 as a leading candidate because of its 82.7 score on Terminal-Bench 2.0.
• For browsing-heavy research, compare GPT-5.5 with Gemini 3.1 Pro and Mythos Preview, which score higher on BrowseComp.
• For documents, spreadsheets and office workflows, give GPT-5.5 serious attention because OpenAI highlights those areas and GPT-5.5 leads the cited OfficeQA Pro comparison.

Final verdict

GPT-5.5 is a very strong model. The public results show top-tier performance in terminal workflows, math and reasoning, office-oriented tasks and knowledge work. OpenAI’s own positioning also points to a model built for practical, multi-step work across code, research, data, documents, spreadsheets and software tools.

The catch is that GPT-5.5 is not a universal winner. Claude Opus 4.7 performs better on SWE-Bench Pro, while Gemini 3.1 Pro and Mythos Preview outperform it on BrowseComp; Mythos Preview also edges it on OSWorld-Verified.

So the most balanced conclusion is this: GPT-5.5 is one of the best all-around AI models in the public benchmark picture, but the smartest way to use it is not blind loyalty. Use it as a top candidate, then test it against the tasks that actually matter to you.