Model comparison
Claude Sonnet 4.5 vs GPT-5.3-Codex-Spark
Head-to-head evidence from 0 shared benchmark results across 0 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Claude Sonnet 4.5 #98 (Estimated); GPT-5.3-Codex-Spark #79 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude Sonnet 4.5 and GPT-5.3-Codex-Spark share 0 comparable benchmark results. 0 of 8 categories are comparable. 12 results are unique to Claude Sonnet 4.5; 0 to GPT-5.3-Codex-Spark.
Updated July 28, 2026- Shared results
- 0
- Claude Sonnet 4.5 only
- 12
- GPT-5.3-Codex-Spark only
- 0
- Comparable categories
- 0 / 8
Benchmark data for Claude Sonnet 4.5 and GPT-5.3-Codex-Spark is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 0 shared benchmark results across 0 evidence categories; 0 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
BenchLM does not have sourced benchmark coverage for GPT-5.3-Codex-Spark yet. This comparison is currently limited to metadata such as context window, reasoning mode, and pricing where available.
GPT-5.3-Codex-Spark has the larger context window at 256K, compared with 200K for Claude Sonnet 4.5.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Claude Sonnet 4.5 | GPT-5.3-Codex-Spark | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude Sonnet 4.5$3 input / $15 output | GPT-5.3-Codex-SparkNot available | A complete price comparison is not available. |
| Generation speedtokens per second | Claude Sonnet 4.5Not available | GPT-5.3-Codex-SparkNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude Sonnet 4.5Not available | GPT-5.3-Codex-SparkNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude Sonnet 4.5200K | GPT-5.3-Codex-Spark256K | GPT-5.3-Codex-Spark lists the larger context window. |
Benchmark Deep Dive
Agentic5 benchmarks
Coding1 benchmarks
| Benchmark | Claude Sonnet 4.5 | GPT-5.3-Codex-Spark | Result |
|---|---|---|---|
| SWE-bench VerifiedSource | 77.2% | — | Not comparable |
Reasoning1 benchmarks
| Benchmark | Claude Sonnet 4.5 | GPT-5.3-Codex-Spark | Result |
|---|---|---|---|
| ARC-AGI-2Source | 13.6% | — | Not comparable |
Knowledge1 benchmarks
| Benchmark | Claude Sonnet 4.5 | GPT-5.3-Codex-Spark | Result |
|---|---|---|---|
| GPQASource | 83.4% | — | Not comparable |
Math3 benchmarks
Multimodal1 benchmarks
| Benchmark | Claude Sonnet 4.5 | GPT-5.3-Codex-Spark | Result |
|---|---|---|---|
| Design Arena WebsiteSource | 1215 | — | Not comparable |
Frequently Asked Questions (3)
Can I compare Claude Sonnet 4.5 and GPT-5.3-Codex-Spark on BenchLM yet?
Not fully yet. BenchLM is tracking both models, but the sourced benchmark breakdown for this comparison is still coming soon.
Why does this comparison show “coming soon”?
BenchLM only shows category winners and benchmark-level calls when we have sourced results that can be compared fairly. For these models, the public benchmark coverage is not complete enough yet.
What data is available for Claude Sonnet 4.5 and GPT-5.3-Codex-Spark today?
Claude Sonnet 4.5: $3.00 input / $15.00 output per 1M tokens GPT-5.3-Codex-Spark: Pricing unavailable Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.
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