Compare/GPT-5.3 Codex (xhigh) vs Claude Sonnet 4.6 (Non-reasoning, Low Effort)

GPT-5.3 Codex (xhigh)vsClaude Sonnet 4.6 (Non-reasoning, Low Effort)

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

OpenAI

GPT-5.3 Codex (xhigh)

Input
$1.75/M
Output
$14/M
Speed
81 tok/s
TTFT
68.19s
Anthropic

Claude Sonnet 4.6 (Non-reasoning, Low Effort)

Input
$3/M
Output
$15/M
Speed
51 tok/s
TTFT
1.16s

Winner by Category

Cheaper
GPT-5.3 Codex (xhigh)
Faster (tok/s)
GPT-5.3 Codex (xhigh)
Lower Latency
Claude Sonnet 4.6 (Non-reasoning, Low Effort)
Benchmarks (7-0)
GPT-5.3 Codex (xhigh)

Pricing Comparison

MetricGPT-5.3 Codex (xhigh)Claude Sonnet 4.6 (Non-reasoning, Low Effort)
Input ($/M tokens)$1.75$3
Output ($/M tokens)$14$15
Cost for 1M input + 100K output tokens:
GPT-5.3 Codex (xhigh)$3.15
Claude Sonnet 4.6 (Non-reasoning, Low Effort)$4.50

Speed Comparison

Output Speed (tokens/s) — higher is better
GPT-5.3 Codex (xhigh)
81 tok/s
Claude Sonnet 4.6 (Non-reasoning, Low Effort)
51 tok/s
Time to First Token (seconds) — lower is better
GPT-5.3 Codex (xhigh)
68.19s
Claude Sonnet 4.6 (Non-reasoning, Low Effort)
1.16s

Benchmark Comparison

Data from Artificial Analysis API — 12 benchmarks

Intelligence Index
54.042.6
Coding Index
53.143.0
Math Index
GPQA Diamond
91.5%79.7%
MMLU-Pro
LiveCodeBench
AIME 2025
MATH-500
Humanity's Last Exam
39.9%10.8%
SciCode
53.2%44.1%
IFBench
75.4%42.4%
TerminalBench
53.0%42.4%
GPT-5.3 Codex (xhigh)7 wins
0 winsClaude Sonnet 4.6 (Non-reasoning, Low Effort)

Frequently Asked Questions

Which is cheaper, GPT-5.3 Codex (xhigh) or Claude Sonnet 4.6 (Non-reasoning, Low Effort)?

GPT-5.3 Codex (xhigh) is cheaper overall. Its blended price (3:1 input/output ratio) is $4.81/M tokens vs $6.00/M for Claude Sonnet 4.6 (Non-reasoning, Low Effort).

Which model performs better on benchmarks?

GPT-5.3 Codex (xhigh) wins 7 out of 12 benchmarks compared to 0 for Claude Sonnet 4.6 (Non-reasoning, Low Effort). See the detailed benchmark chart above for per-category results.

Which is faster for real-time applications?

GPT-5.3 Codex (xhigh) generates tokens faster at 81 tok/s vs 51 tok/s. However, Claude Sonnet 4.6 (Non-reasoning, Low Effort) has lower time-to-first-token (1.16s vs 68.19s).

When should I use GPT-5.3 Codex (xhigh) vs Claude Sonnet 4.6 (Non-reasoning, Low Effort)?

Choose based on your priorities: GPT-5.3 Codex (xhigh) for lower cost, GPT-5.3 Codex (xhigh) for stronger benchmark performance, and GPT-5.3 Codex (xhigh) for faster generation. For latency-sensitive apps, check the TTFT comparison above.