Comparison
Opus 4.7 vs GPT-5.5 vs Gemini 3.1 Pro for Coding
Side-by-side Claude Opus 4.7 vs GPT-5.5 vs Gemini 3.1 Pro for coding in 2026. SWE-bench scores, context windows, agent integration, MCP support, and pricing.
Short answer
Claude Opus 4.7 leads on long-context multi-file refactors and agentic SWE-bench. GPT-5.5 leads on raw generation speed and ChatGPT integration. Gemini 3.1 Pro leads on 1M+ native context, multimodal reasoning, and Google ecosystem integration. All three landed April 2026, pick by ecosystem and use case.
Claude Opus 4.7
Anthropic
Anthropic's flagship coding model (April 2026)
Best for: Long-context multi-file refactors, agentic SWE-bench leadership, production agent runs.
Visit Claude Opus 4.7 →GPT-5.5
OpenAI
OpenAI's flagship coding model (April 2026)
Best for: Raw generation speed, tight ChatGPT integration, multimodal output.
Visit GPT-5.5 →Gemini 3.1 Pro
Google's flagship 1M+ context coding model (April 2026)
Best for: Massive context windows (2M+ in some configs), Google ecosystem, multimodal reasoning.
Visit Gemini 3.1 Pro →Feature comparison
| Feature | Claude Opus 4.7 | GPT-5.5 | Gemini 3.1 Pro |
|---|---|---|---|
| Vendor | Anthropic | OpenAI | |
| Released | April 2026 | April 2026 | April 2026 |
| Context window | 1M (Opus 4.7 1M) | 1M | Edge2M+ in some configs |
| SWE-bench leadership | Top, multi-file & agentic | Top, single-file & speed | Top, long-context |
| Native agent tool | Claude Code | OpenAI Codex CLI | Antigravity 2.0 |
| MCP support | EdgeFirst-class (Anthropic created MCP) | Yes (via Codex CLI) | Yes (via Antigravity) |
| Voice mode | Yes (Claude Code /voice) | Yes (ChatGPT voice) | Yes (Antigravity voice) |
| Free tier | Limited (Claude.ai) | ChatGPT free | EdgeGemini free + Gemini CLI |
| Pricing (API) | Premium tier | Mid tier | Mid tier |
Vendor
Released
Context window
SWE-bench leadership
Native agent tool
MCP support
Voice mode
Free tier
Pricing (API)
Pick Claude Opus 4.7 when
- →You want the strongest long-context multi-file coding model
- →You want native MCP and SKILL.md ecosystem support
- →You're shipping production agent runs with Claude Code
- →You're already on Claude Pro/Max
Pick GPT-5.5 when
- →You're on ChatGPT Pro and want raw generation speed
- →You want best multimodal output (image, audio, video)
- →You prefer open-source agent code (Codex CLI is Apache 2.0)
- →Your team is on the OpenAI / Microsoft stack
Pick Gemini 3.1 Pro when
- →You need 2M+ token context windows
- →You're on Google's stack (Vertex AI, Workspace, Gemini)
- →You want the most generous free tier (Gemini CLI)
- →You're trying Antigravity 2.0's multi-agent architecture
Verdict
All three are at the top of SWE-bench depending on the variant. Pick Opus 4.7 if you do long-context multi-file work and want native MCP + skills. Pick GPT-5.5 if you're on ChatGPT and want raw speed + multimodal output. Pick Gemini 3.1 Pro if you're on Google's stack or need 2M+ context. For agent runs, the model tier matters less than the agent (Claude Code vs Codex vs Antigravity).
Frequently asked questions
Which model is best at coding in 2026?
There's no single winner. Opus 4.7 leads on long-context agentic SWE-bench; GPT-5.5 leads on raw speed; Gemini 3.1 Pro leads on context window and multimodal reasoning. The bigger differentiator is the agent, Claude Code, Codex CLI, or Antigravity 2.0.
Which has the longest context window?
Gemini 3.1 Pro at 2M+ in some configurations. Opus 4.7 1M and GPT-5.5 1M are both at 1M for general use.
Is Gemini 3.5 Flash worth using?
Yes for speed-sensitive tasks. Gemini 3.5 Flash launched May 19, 2026 at Google I/O alongside Antigravity 2.0, it's the fast/cheap variant of Gemini 3.1 Pro.
Which model has the best MCP support?
Opus 4.7 / Claude Code, Anthropic created MCP and has the deepest integration. GPT and Gemini both support MCP via their respective agents (Codex CLI, Antigravity 2.0).
Can I switch between models in the same tool?
Yes via Cursor, Continue.dev, or Cline, all support all three. Cursor's Composer 2.5 (May 18, 2026) added improved model switching.
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