Quick Answer
Gemini 3.5 Pro vs Claude Opus 5 vs GPT-5.6 Sol
The Short Answer
Two of these three you can use today; one you can’t. As of late July 2026, Gemini 3.5 Pro is still not GA (estimated ~$15/$60, “coming soon” badge, no firm date). Claude Opus 5 (launched July 24) and GPT-5.6 Sol are both fully available — so for anything shipping now, the real decision is Opus 5 vs Sol.
Head-to-Head
| Gemini 3.5 Pro | Claude Opus 5 | GPT-5.6 Sol | |
|---|---|---|---|
| Status | ❌ not GA (est.) | ✅ GA Jul 24 | ✅ GA |
| API in/out ($/MTok) | ~$15 / $60 (est.) | $5 / $25 | $5 / $30 |
| SWE-bench Pro | unknown | 79.2% | 64.6% |
| SWE-bench Verified | unknown | ~97% | ~96.2% |
| Coding Agent Index | unknown | 78 | 80 (leads) |
| Context | large | 1M | large |
What to Use Today
- Claude Opus 5 — best for agentic coding, computer use, long-horizon refactors, and the effort toggle (low→max). Leads SWE-bench Pro and Frontier-Bench, and it’s the cheaper output tier of the two shipping flagships.
- GPT-5.6 Sol — best for verified/terminal coding and the raw coding-agent index. Slightly pricier output ($30/MTok), with Sol Ultra ($12.50/$75) for the hardest tasks.
- Google, but today — since 3.5 Pro isn’t GA, use Gemini 3.6 Flash ($1.50/$7.50, the new default) or Gemini 3.1 Pro ($2/$12) for long-context work.
Should You Wait for Gemini 3.5 Pro?
For evaluation, sure — bookmark it. For production, no. It has slipped repeatedly (partly amid senior-researcher departures to Anthropic), still shows a “coming soon” badge, and its ~$15/$60 estimate would make it the most expensive of the three by a wide margin. Build on Opus 5 or GPT-5.6 Sol now and re-test 3.5 Pro the day it actually reaches GA.
Sources
- Anthropic — Claude Opus 5 (July 24, 2026): anthropic.com/news/claude-opus-5
- Google — Gemini API pricing: ai.google.dev/pricing
- getbind — Gemini 3.5 Pro slips to July: blog.getbind.co
- Vals AI — SWE-bench Verified leaderboard: vals.ai/benchmarks/swebench