GPT-5.5 Pro vs Claude Opus 4.7 vs DeepSeek V4-Pro Max (2026)
GPT-5.5 Pro vs Claude Opus 4.7 vs DeepSeek V4-Pro Max (2026)
By late April 2026, three models share the absolute frontier for hard reasoning problems: OpenAI’s GPT-5.5 Pro, Anthropic’s Claude Opus 4.7, and DeepSeek’s new V4-Pro Max (V4-Pro at maximum reasoning effort). Here’s how they actually compare on the work that matters.
Last verified: April 26, 2026
TL;DR
| GPT-5.5 Pro | Claude Opus 4.7 | DeepSeek V4-Pro Max | |
|---|---|---|---|
| Released | April 23, 2026 | March 2026 | April 24, 2026 |
| Type | Closed | Closed | Open weights |
| Context | 400K | 1M | 1M |
| FrontierMath Tier 4 | 39.6% | ~32% | ~31% |
| HLE with tools | 57.2% | ~52% | ~50% |
| BrowseComp | 90.1% | ~78% | ~70% |
| SWE-bench Verified | ~78% | 80.8% | 80.6% |
| Terminal-Bench 2.0 | 82.7% (Codex) | 65.4% | 67.9% (V4-Pro) |
| MMLU-Pro | 87.5% | 86.4% | 83.2% |
| GPQA Diamond | 84.5% | 81.2% | 78.6% |
| AIME 2026 | 94.2% | 89.4% | 88.4% |
| Input price (per 1M) | $30 | ~$15 | ~$2 (DeepInfra) |
| Output price (per 1M) | $180 | ~$75 | ~$4 |
| Best for | Hardest reasoning, math | Long agent runs, coding | Coding + cost |
Where GPT-5.5 Pro wins
1. The hardest reasoning problems
- FrontierMath Tier 4: 39.6% — the highest score any publicly available model has posted. Tier 4 problems are research-level and unsolved by most PhD mathematicians.
- HLE with tools: 57.2% — the Humanity’s Last Exam benchmark with tool access; GPT-5.5 Pro is currently the leader.
- AIME 2026: 94.2% — near-perfect on competition math.
If your workload involves novel math or science research questions, GPT-5.5 Pro is the right choice today.
2. BrowseComp and tool-using research
BrowseComp at 90.1% — Pro’s tool use, especially for long multi-step web research, is markedly stronger than the others. This shows up in deep research products (ChatGPT Deep Research, Perplexity Pro Search) where GPT-5.5 Pro is the leader.
3. Best frontier reasoning generalist
On a weighted average of MMLU-Pro, GPQA Diamond, AIME, and FrontierMath, GPT-5.5 Pro is currently the best generalist reasoner.
Where Claude Opus 4.7 wins
1. Autonomous coding agents
SWE-bench Verified: 80.8% — the highest score for any model on the most credible real-world coding benchmark. Claude Code Opus 4.7 is the de facto standard for long autonomous coding sessions.
2. Long-running tool use stability
Claude’s extended thinking + tool use loop is best-in-class for tasks that run for hours without human intervention. The model is much less likely to:
- Drift off-task
- Get stuck in tool-call loops
- Make ungrounded assumptions
3. Long context coherence
At 1M context, Claude Opus 4.7’s needle-in-haystack and code-in-haystack performance is excellent — better than V4-Pro Max above ~500K tokens.
4. Safety and refusal calibration
For regulated industries (healthcare, legal, finance), Claude’s calibration is widely seen as the best. Constitutional AI shows up in real production behavior.
Where DeepSeek V4-Pro Max wins
1. Cost
~50× cheaper output tokens than GPT-5.5 Pro ($4 vs $180). Even vs Claude Opus 4.7, it’s a 19× reduction. For high-volume reasoning workloads, this is decisive.
2. Best open-source frontier
V4-Pro Max is the strongest open-weight model in April 2026 — top knowledge benchmarks among open models, only trailing Gemini 3.1 Pro.
3. Self-host or audit
Want to run a frontier reasoner on Huawei Ascend, AWS Trainium, or your own multi-node cluster? V4-Pro Max is the only realistic option in this top-3.
4. Coding performance at the frontier
Terminal-Bench 2.0: 67.9% beats both Opus 4.7 and (non-Codex) GPT-5.5. LiveCodeBench: 93.5% leads the field. SWE-bench Verified is essentially tied with Opus 4.7.
Pricing math: a real reasoning workload
Imagine an enterprise agent running 1M reasoning steps per month, averaging 3K input + 5K output per step (3B input + 5B output total):
| Model | Monthly cost |
|---|---|
| GPT-5.5 Pro | $90,000 in + $900,000 out = $990,000 |
| Claude Opus 4.7 | $45,000 in + $375,000 out = $420,000 |
| DeepSeek V4-Pro Max | $6,000 in + $20,000 out = $26,000 |
The cost gap is so wide it changes what’s economically viable. Workloads that are uneconomic on GPT-5.5 Pro become routine on V4-Pro Max.
Architecture
| GPT-5.5 Pro | Claude Opus 4.7 | DeepSeek V4-Pro Max | |
|---|---|---|---|
| Type | Undisclosed | Undisclosed | MoE, 1.6T total / 49B active |
| Training | OpenAI custom | Anthropic custom | Mixed Nvidia + Huawei Ascend |
| Reasoning mode | Built-in tool-use loop | Extended thinking + tools | Max reasoning effort flag |
| Open weights | ❌ | ❌ | ✅ |
| Multimodal | Limited | Text + images | Text only |
Which model for which task?
Hard math, science, frontier research
→ GPT-5.5 Pro. The FrontierMath Tier 4 lead is real and matters here.
Long autonomous coding sessions
→ Claude Opus 4.7 (or DeepSeek V4-Pro Max if cost matters). Within 1 percentage point on SWE-bench Verified; pick by infrastructure preference.
Cost-sensitive frontier reasoning at scale
→ DeepSeek V4-Pro Max. There is no closed alternative that approaches its price-quality frontier.
Web research and Browse-style agents
→ GPT-5.5 Pro. BrowseComp 90.1% is the dominant lead.
Regulated industries with safety-first procurement
→ Claude Opus 4.7. The safety story and calibration win here.
Self-hosted / sovereign / audit-required deployments
→ DeepSeek V4-Pro Max. The only top-3 with open weights.
Multimodal frontier work
→ None of these — use Gemini 3.1 Pro instead. All three top reasoners are text-strong but trail Gemini on vision/video/audio.
The hybrid play (most teams in 2026)
Production stacks rarely pick one. A common 2026 pattern:
- DeepSeek V4-Pro Max for default reasoning (cheap, frontier-grade)
- Claude Opus 4.7 for long coding tasks and high-stakes safety-sensitive work
- GPT-5.5 Pro for the hardest math/science questions and Browse research
Routed via OpenRouter or LiteLLM, this stack costs about 8–15% of an all-Opus or all-GPT-5.5-Pro deployment with no measurable quality regression on most workloads.
What’s coming next
- Anthropic is expected to ship a Mythos-derived Opus successor in Q2/Q3 2026 — likely closing the FrontierMath gap
- OpenAI is hinting at a “GPT-5.5 super app” combining ChatGPT, Codex, and a browser; pricing may compress
- DeepSeek typically ships V-series updates every 6–9 months; V4 is the floor, not the ceiling
- Gemini 3.2 is rumored for late Q2; if it lands strong on coding, it joins this comparison
Bottom line
In April 2026, the “best frontier model” depends entirely on the task and budget. GPT-5.5 Pro wins the hardest problems. Claude Opus 4.7 wins long autonomous coding. DeepSeek V4-Pro Max wins on cost while matching the closed frontier on most benchmarks.
The smart play is to use all three behind a router and let each task pick the cheapest model that can solve it.
Last verified: April 26, 2026. Sources: OpenAI GPT-5.5 release notes (April 23, 2026), Anthropic model card for Claude Opus 4.7, api-docs.deepseek.com (DeepSeek V4 release April 24, 2026), DeepInfra deepseek-ai/DeepSeek-V4-Pro pricing, Artificial Analysis benchmarks, FrontierMath / SWE-bench Verified / Terminal-Bench 2.0 leaderboards.