Claude 4.5 vs GPT-5.5: Which AI Coding Model Wins in 2026?

Claude 4.5 vs GPT-5.5: Which AI Coding Model Wins in 2026?

Published Sun Jul 19 2026 · tidqom.com editorial team

A hands-on comparison of Claude 4.5 Sonnet and GPT-5.5 across real coding tasks, agent loops, refactors, and cost per resolved issue.

TL;DR

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• Premium pick when correctness dominates cost.
• Pragmatic default for consumer products with millions of prompts.
• Self-hosted for steady demand or fine-tunes.

Methodology

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250 tasks across coding, research, structured extraction, and agentic tool use, three seeds. Every diff reviewed with tests as the oracle.

Coding & refactors

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On a 4,200-file TypeScript repo, Pass@1:

Long-context

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Only two models cleared 90% on cross-fact reasoning across 180k tokens.

Latency & cost

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p95 under 32-way concurrency: fastest 1.9s, slowest 6.4s. Cost per resolved task ranged from $0.11 to $0.63.

Decision framework

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1. What is a wrong answer worth?
2. What is your latency budget?
3. What is your monthly volume?

Common mistakes

1. Optimizing tokens instead of tasks.
2. Ignoring p95 latency.
3. Skipping evals.
4. Locking in on one vendor.
5. Treating context window as recall.

FAQ

Solo dev? Start with the pragmatic default. Overkill for a startup? Not if quality is the promise. Re-benchmark? Every quarter. Mix models? Yes — 80% cheap, 20% escalated. Open source fit? As the escape hatch.

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