Model comparison
GPT-5 (medium) vs Grok Code Fast 1
Head-to-head evidence from 11 shared benchmark results across 5 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: GPT-5 (medium) #84 (Supported); Grok Code Fast 1 #180 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. GPT-5 (medium) and Grok Code Fast 1 share 11 comparable benchmark results. 0 of 8 categories are comparable. 3 results are unique to GPT-5 (medium); 1 to Grok Code Fast 1.
Updated July 20, 2026- Shared results
- 11
- GPT-5 (medium) only
- 3
- Grok Code Fast 1 only
- 1
- Comparable categories
- 0 / 8
Benchmark data for GPT-5 (medium) and Grok Code Fast 1 is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 11 shared benchmark results across 5 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 has partial data for these models, but not enough overlapping benchmark coverage to produce a fair score-level comparison yet.
Grok Code Fast 1 has the larger context window at 256K, compared with 128K for GPT-5 (medium).
Category breakdown
Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.
| Category | GPT-5 (medium) | Δ | Grok Code Fast 1 |
|---|---|---|---|
| Coding | GPT-5 (medium)Not measured | MarginNo overlap | Grok Code Fast 170.8 |
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | GPT-5 (medium) | Grok Code Fast 1 | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | GPT-5 (medium)Not available | Grok Code Fast 1$0.2 input / $1.5 output | A complete price comparison is not available. |
| Generation speedtokens per second | GPT-5 (medium)83 tok/s | Grok Code Fast 1172 tok/s | Grok Code Fast 1 has the higher measured throughput. |
| First-answer latencyseconds to first token | GPT-5 (medium)36.28 s | Grok Code Fast 12.81 s | Grok Code Fast 1 reaches the first token sooner. |
| Context windowmaximum listed tokens | GPT-5 (medium)128K | Grok Code Fast 1256K | Grok Code Fast 1 lists the larger context window. |
Benchmark Deep Dive
Agentic1 benchmarks
| Benchmark | GPT-5 (medium) | Grok Code Fast 1 | Result |
|---|---|---|---|
| τ²-bench resultsSource | 86.5% | 75.7% | GPT-5 (medium) leads |
Coding2 benchmarks
Reasoning2 benchmarks
Knowledge6 benchmarks
| Benchmark | GPT-5 (medium) | Grok Code Fast 1 | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 33.7% | 21.6% | GPT-5 (medium) leads |
| AA-GPQA DiamondSource | 84.2% | 72.7% | GPT-5 (medium) leads |
| AA-HLESource | 23.5% | 7.5% | GPT-5 (medium) leads |
| AA-Omniscience IndexSource | -10.1% | -36.0% | GPT-5 (medium) leads |
| AA-Omniscience AccuracySource | 38.9% | 23.8% | GPT-5 (medium) leads |
| AA-Omniscience Hallucination RateSource | 80.1% | 78.5% | Grok Code Fast 1 leads |
Math1 benchmarks
| Benchmark | GPT-5 (medium) | Grok Code Fast 1 | Result |
|---|---|---|---|
| AA MATH-500Source | 99.1% | — | Not comparable |
Multimodal2 benchmarks
Inst. Following1 benchmarks
| Benchmark | GPT-5 (medium) | Grok Code Fast 1 | Result |
|---|---|---|---|
| AA-IFBenchSource | 70.6% | 41.4% | GPT-5 (medium) leads |
Frequently Asked Questions (3)
Can I compare GPT-5 (medium) and Grok Code Fast 1 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 GPT-5 (medium) and Grok Code Fast 1 today?
GPT-5 (medium): Pricing unavailable Grok Code Fast 1: $0.20 input / $1.50 output per 1M tokens Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.
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