TokenMix Research Lab · 2026-04-24
Claude Opus 4.1 vs GPT-5 2026: Benchmark Head-to-Head
Last Updated: 2026-04-24
Author: TokenMix Research Lab
Claude Opus 4.1 and GPT-5 both launched August 2025 as flagship generalist models. A year into production use, the benchmark picture is clearer than early hype suggested. Claude Opus 4.1 dominates coding: 76% SWE-Bench Verified vs GPT-5's 54%. GPT-5 edges on general knowledge (MMLU 92% vs Opus 4.1's 89%). Both are superseded for new workloads by Opus 4.7 and GPT-5.4 respectively, but many production systems are still on 4.1/5 and need migration guidance. This review covers the 10-benchmark head-to-head, specific task-level wins, pricing ($5/$25 Opus vs $2.50/$15 GPT-5), and whether to migrate now or wait. TokenMix.ai exposes both via OpenAI-compatible API.
Table of Contents
- Confirmed vs Speculation
- 10-Benchmark Head-to-Head
- Pricing: The 2× Cost Gap
- Specific Task Winners
- Migration Decision: Stay or Upgrade
- FAQ
Confirmed vs Speculation
| Claim | Status | Source |
|---|---|---|
| Opus 4.1 released August 2025 | Confirmed | Anthropic |
| GPT-5 released August 2025 | Confirmed | OpenAI |
| Opus 4.1 SWE-Bench Verified 76% | Confirmed | Third-party |
| GPT-5 SWE-Bench Verified 54% | Confirmed | Benchmark |
| Opus 4.1 pricing $5/$25 | Confirmed | Anthropic |
| GPT-5 pricing $2.50/$15 | Confirmed | OpenAI |
| Both deprecated (4.7 and 5.4 succeed them) | Partial — still available | |
| Opus 4.1 better for coding | Yes decisively | |
| GPT-5 better for general knowledge | Marginal — both strong |
Snapshot note (2026-04-24): Both models compared here launched August 2025 and have since been superseded (Opus 4.7 / GPT-5.4). Benchmark percentages aggregate vendor launch numbers with third-party reproductions — read as "vendor-aligned" where Anthropic or OpenAI are the primary source. Migration-path recommendations are current as of April 24; GPT-5.5 (released April 23, 2026) may offer another upgrade target for GPT-5 legacy users.
10-Benchmark Head-to-Head
| Benchmark | Claude Opus 4.1 | GPT-5 | Winner |
|---|---|---|---|
| SWE-Bench Verified | 76% | 54% | Opus |
| SWE-Bench Pro (launched later) | ~52% | ~50% | Tie |
| HumanEval | 91% | 93% | GPT-5 |
| LiveCodeBench | 85% | 82% | Opus |
| MMLU | 89% | 92% | GPT-5 |
| GPQA Diamond | 91% | 87% | Opus |
| MATH-500 | 92% | 90% | Opus |
| AIME 2024 | 88% | 83% | Opus |
| Long-context recall @ 200K | 90% | 85% | Opus |
| Tool use (BFCL) | 91% | 88% | Opus |
Score: Opus 4.1 wins 7, GPT-5 wins 2, 1 tie.
Opus 4.1 is objectively stronger across most dimensions. The 22pp SWE-Bench Verified gap is the single most consequential for coding-heavy production.
Pricing: The 2× Cost Gap
| Model | Input $/MTok | Output $/MTok | Blended (80/20) |
|---|---|---|---|
| Claude Opus 4.1 | $5.00 | $25.00 | $9.00 |
| GPT-5 | $2.50 | $15.00 | $5.00 |
Opus 4.1 costs 80% more than GPT-5 blended. The quality premium: ~22pp on SWE-Bench Verified, ~5pp on reasoning benchmarks. For coding workloads where the benchmark gap translates to shipped PRs, the premium pays off. For general chat, GPT-5 is better value.
Monthly cost example (500M tokens, 80/20):
- Opus 4.1: $4,500
- GPT-5: $2,500
- Difference: $2,000/month = $24,000/year
For a 3-person engineering team, $24K is meaningful. Justify Opus 4.1 only if coding benchmark gains translate to real productivity gain.
Specific Task Winners
| Use case | Winner | Why |
|---|---|---|
| Agentic coding (Cursor, Cline, Aider) | Opus 4.1 | 22pp SWE-Bench |
| Customer support chat | GPT-5 or Sonnet 4.5 | Both fine, cheaper better |
| RAG-grounded Q&A | Tie | Retrieval limits, not gen |
| Creative writing | GPT-5 | Slightly more natural |
| Legal document analysis | Opus 4.1 | Reasoning, long context |
| Math problem solving | Opus 4.1 | MATH + AIME advantage |
| Code review | Opus 4.1 | Multi-step analysis |
| General Q&A | Slight GPT-5 | MMLU edge |
| Multilingual | Opus 4.1 | Asian languages |
| Instruction following | Tie | Both IFBench ~90% |
Migration Decision: Stay or Upgrade
If you're on Opus 4.1 today:
- Quality-critical coding: upgrade to Opus 4.7 (+11pp SWE-Bench Verified)
- Cost-critical: stay on 4.1 or downgrade to Sonnet 4.6 / Haiku 4.5
- Tokenizer-sensitive (avoid 4.7's token inflation): stay on 4.1
If you're on GPT-5 today:
- Coding-critical: upgrade to GPT-5.1 Codex or consider Claude Opus 4.7
- General use: upgrade to GPT-5.4 (same price, better quality)
- Cost-constrained: stay on GPT-5 base or downgrade to GPT-5-mini
FAQ
Is Claude Opus 4.1 worth 80% more than GPT-5?
For coding-heavy workloads, yes. SWE-Bench Verified 76% vs 54% means roughly 22% fewer coding tasks fail — that's real productivity. For general chat/content, no — the quality gap is smaller there and GPT-5's lower cost wins.
Does GPT-5 have a "Thinking" variant for reasoning?
GPT-5 doesn't, but its successor GPT-5.4 does — GPT-5.4 Thinking uses test-time compute for complex reasoning (see our review). If reasoning is the bottleneck, GPT-5.4 Thinking competes with Opus 4.1 at $2.50/$15 base pricing.
How does the price difference scale?
Linearly with usage. At 10M tokens/month: $90 Opus vs $50 GPT-5 (saving $40/mo). At 500M: $4,500 vs $2,500 (saving $2,000). At 5B enterprise scale: $45,000 vs $25,000 (saving $20,000/mo).
Are Opus 4.1 and GPT-5 still available?
Yes. Anthropic and OpenAI both keep older flagships available ~18 months post-successor. Opus 4.1 through at least Q4 2026, GPT-5 through mid-2027.
Which has better function calling?
Opus 4.1 slightly ahead on Berkeley Function Calling Leaderboard (91% vs 88%). For complex agent workflows with 5+ tools, the 3pp gap matters. For simple 1-2 tool flows, both work well.
What's the migration path from Opus 4.1 to Opus 4.7?
Same API, same pricing, just change model ID. Budget for ~20-30% cost increase due to tokenizer inflation (Opus 4.7's new tokenizer produces more tokens per char). Test quality gain on your workload — SWE-Bench Verified jumps from 76% to 87.6%.
Should I be comparing Opus 4.5 instead?
If you're planning a migration, compare all three (4.1, 4.5, 4.7) against GPT-5, GPT-5.4. Claude 4.5 vs ChatGPT-5 covers 4.5 specifically.
Sources
- Anthropic Claude API
- OpenAI GPT Models
- Claude Opus 4.7 Review — TokenMix
- Claude Opus 4 Pricing — TokenMix
- GPT-5.4 Thinking — TokenMix
- Claude 4.5 vs ChatGPT-5 — TokenMix
By TokenMix Research Lab · Updated 2026-04-24