Is Claude Opus 4.8 better than GPT-5.5?

Neither model is universally better. Opus 4.8 and GPT-5.5 have different ecosystems, tool behavior, safety responses, and task profiles. Run both on representative work with the same evidence and rubric, then compare accuracy, review effort, latency, reliability, and total cost.

Which model is better for coding?

Both target advanced software work. Claude Opus 4.8 integrates closely with Claude Code, while GPT-5.5 is central to Codex. Repository-specific evaluations matter more than isolated benchmark rankings because harnesses, tools, tests, and project conventions strongly influence coding results.

Which model is cheaper?

Both list $5 per million standard input tokens. Opus 4.8 lists $25 per million output tokens and GPT-5.5 lists $30. Effective cost depends on caching, batch or fast processing, token efficiency, retries, tool calls, and correction time, so compare cost per accepted task.

Can I use the same prompt for Claude and GPT-5.5?

Yes, begin with a model-neutral prompt defining goal, context, constraints, evidence, output schema, and acceptance tests. Some tool and effort settings are provider-specific, so keep those in a separate adapter rather than embedding them in the core task instructions.

Claude Opus 4.8 vs GPT-5.5: Which Model Should You Use?

Compare Claude Opus 4.8 and GPT-5.5 using official capabilities, API pricing, context, coding workflows, safeguards, and practical selection criteria.

By Quantara Editorial Team · AI Tools · Published Jun 21, 2026 · 10 min read

Claude Opus 4.8 and GPT-5.5 are premium models built for serious coding, agents, and professional work. A useful comparison cannot come from one synthetic score. The right choice depends on task success, tool environment, context, price, latency, safety behavior, and how easily a team can verify the result.

Quick Comparison

Factor	Claude Opus 4.8	GPT-5.5
Standard API price	$5 input / $25 output per 1M tokens	$5 input / $30 output per 1M tokens
Documented context	Up to 1M tokens	1M API; 400K in Codex
Primary positioning	Coding, agents, long-running professional work	Agentic coding, computer use, knowledge and scientific work
Key ecosystem	Claude, Claude Code, Cowork, cloud marketplaces	ChatGPT, Codex, Responses API

Claude Opus 4.8 Strengths

Anthropic positions Opus 4.8 as a hybrid reasoning model with consistency and autonomy for long-running tasks. It is available in Claude, the Claude API, and major cloud platforms. Claude Code and Cowork provide focused agent environments for software and knowledge work, while effort controls let users trade speed and usage for deeper reasoning.

GPT-5.5 Strengths

OpenAI positions GPT-5.5 around agentic coding, computer use, professional work, and scientific research. Its release reports 82.7% on Terminal-Bench 2.0 and 58.6% on SWE-Bench Pro, with the important caveat that benchmark harnesses materially affect results. GPT-5.5 is integrated across ChatGPT and Codex and supports long-running work with tools.

Which Is Better for Coding?

Test both on your repositories. Use real issues, architecture constraints, security rules, and the exact harness your team will deploy. Measure correct patches, tests passed, review effort, regressions, token use, and elapsed time. Vendor benchmark tables use different configurations and should guide evaluation, not replace it.

Which Is Better for Writing and Analysis?

Opus 4.8 is a natural fit for teams already using Claude for long-form work and local desktop workflows. GPT-5.5 is compelling when the task crosses research, files, computer interaction, and structured deliverables inside ChatGPT or Codex. Give both the same source pack and rubric, then blind-review outputs.

Price and Total Cost

The standard input price is the same, while GPT-5.5 lists a higher output price. This does not establish the cheaper workflow. Caching, token efficiency, retries, tool calls, fast modes, batch processing, and reviewer corrections can reverse the result. Compare cost per accepted task.

Decision Guide

Choose Opus 4.8 when Claude Code, Cowork, or Anthropic cloud deployment fits the workflow.
Choose GPT-5.5 when Codex, ChatGPT tools, computer use, or OpenAI APIs are central.
Keep both when availability and task diversity matter.
For high-stakes work, require sources, deterministic checks, and human approval regardless of model.

Create a Fair Comparison Prompt

Use Verbito's AI Prompt Generator to create one model-neutral brief, acceptance rubric, and output schema for side-by-side testing.

Sources

Frequently asked questions

Is Claude Opus 4.8 better than GPT-5.5?: Neither model is universally better. Opus 4.8 and GPT-5.5 have different ecosystems, tool behavior, safety responses, and task profiles. Run both on representative work with the same evidence and rubric, then compare accuracy, review effort, latency, reliability, and total cost.
Which model is better for coding?: Both target advanced software work. Claude Opus 4.8 integrates closely with Claude Code, while GPT-5.5 is central to Codex. Repository-specific evaluations matter more than isolated benchmark rankings because harnesses, tools, tests, and project conventions strongly influence coding results.
Which model is cheaper?: Both list $5 per million standard input tokens. Opus 4.8 lists $25 per million output tokens and GPT-5.5 lists $30. Effective cost depends on caching, batch or fast processing, token efficiency, retries, tool calls, and correction time, so compare cost per accepted task.
Can I use the same prompt for Claude and GPT-5.5?: Yes, begin with a model-neutral prompt defining goal, context, constraints, evidence, output schema, and acceptance tests. Some tool and effort settings are provider-specific, so keep those in a separate adapter rather than embedding them in the core task instructions.