Compare/GPT-5.5 Instant (June 2026) vs Claude Opus 4.5 (Reasoning)

GPT-5.5 Instant (June 2026)vsClaude Opus 4.5 (Reasoning)

Side-by-side comparison of pricing, 12 benchmarks, and generation speed.

OpenAI

GPT-5.5 Instant (June 2026)

Input
$5/M
Output
$30/M
Speed
TTFT
Anthropic

Claude Opus 4.5 (Reasoning)

Input
$5/M
Output
$25/M
Speed
62 tok/s
TTFT
10.70s

Winner by Category

Cheaper
Claude Opus 4.5 (Reasoning)
Faster (tok/s)
Claude Opus 4.5 (Reasoning)
Lower Latency
GPT-5.5 Instant (June 2026)
Benchmarks (1-10)
Claude Opus 4.5 (Reasoning)

Pricing Comparison

MetricGPT-5.5 Instant (June 2026)Claude Opus 4.5 (Reasoning)
Input ($/M tokens)$5$5
Output ($/M tokens)$30$25
Cost for 1M input + 100K output tokens:
GPT-5.5 Instant (June 2026)$8.00
Claude Opus 4.5 (Reasoning)$7.50

Speed Comparison

Output Speed (tokens/s) — higher is better
GPT-5.5 Instant (June 2026)
Claude Opus 4.5 (Reasoning)
62 tok/s
Time to First Token (seconds) — lower is better
GPT-5.5 Instant (June 2026)
Claude Opus 4.5 (Reasoning)
10.70s

Benchmark Comparison

Data from Artificial Analysis API — 12 benchmarks

Intelligence Index
28.940.8
Coding Index
39.4
Math Index
91.3
GPQA Diamond
82.3%86.6%
MMLU-Pro
89.5%
LiveCodeBench
87.1%
AIME 2025
91.3%
MATH-500
Humanity's Last Exam
18.6%28.4%
SciCode
48.6%49.5%
IFBench
58.0%
TerminalBench
47.0%
GPT-5.5 Instant (June 2026)1 wins
10 winsClaude Opus 4.5 (Reasoning)

Frequently Asked Questions

Which is cheaper, GPT-5.5 Instant (June 2026) or Claude Opus 4.5 (Reasoning)?

Claude Opus 4.5 (Reasoning) is cheaper overall. Its blended price (3:1 input/output ratio) is $10.00/M tokens vs $11.25/M for GPT-5.5 Instant (June 2026).

Which model performs better on benchmarks?

Claude Opus 4.5 (Reasoning) wins 10 out of 12 benchmarks compared to 1 for GPT-5.5 Instant (June 2026). See the detailed benchmark chart above for per-category results.

Which is faster for real-time applications?

Claude Opus 4.5 (Reasoning) generates tokens faster at 62 tok/s vs 0 tok/s. GPT-5.5 Instant (June 2026) also has lower time-to-first-token (0.00s vs 10.70s).

When should I use GPT-5.5 Instant (June 2026) vs Claude Opus 4.5 (Reasoning)?

Choose based on your priorities: Claude Opus 4.5 (Reasoning) for lower cost, Claude Opus 4.5 (Reasoning) for stronger benchmark performance, and Claude Opus 4.5 (Reasoning) for faster generation. For latency-sensitive apps, check the TTFT comparison above.