Model comparison
DeepSeek V4 Flash vs Grok 4.20
Head-to-head evidence from 6 shared benchmark results across 4 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: DeepSeek V4 Flash #61 (Estimated); Grok 4.20 #88 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. DeepSeek V4 Flash and Grok 4.20 share 6 comparable benchmark results. 2 of 8 categories are comparable. 16 results are unique to DeepSeek V4 Flash; 12 to Grok 4.20.
Updated July 23, 2026- Shared results
- 6
- DeepSeek V4 Flash only
- 16
- Grok 4.20 only
- 12
- Comparable categories
- 2 / 8
Pick DeepSeek V4 Flash if you want the stronger benchmark profile. Grok 4.20 only becomes the better choice if coding is the priority or you need the larger 2M context window.
Confidence note. This is a partial-evidence comparison with 6 shared benchmark results across 4 evidence categories; 2 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
DeepSeek V4 Flash is clearly ahead on the BenchAlign aggregate, 58.88 to 54.68. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
DeepSeek V4 Flash's sharpest advantage is in agentic, where it averages 49.1 against 47.1. The single biggest benchmark swing on the page is SWE-bench Verified, 73.7% to 76.7%. Grok 4.20 does hit back in coding, so the answer changes if that is the part of the workload you care about most.
Grok 4.20 is also the more expensive model on tokens at $2.00 input / $6.00 output per 1M tokens, versus $0.14 input / $0.28 output per 1M tokens for DeepSeek V4 Flash. That is roughly 21.4x on output cost alone. Grok 4.20 is the reasoning model in the pair, while DeepSeek V4 Flash is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. Grok 4.20 gives you the larger context window at 2M, compared with 1M for DeepSeek V4 Flash.
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 | DeepSeek V4 Flash | Δ | Grok 4.20 |
|---|---|---|---|
| Coding | DeepSeek V4 Flash64.2 | Margin→ 2.9 | Grok 4.2067.1 |
| Agentic | DeepSeek V4 Flash49.1 | Margin← 2.0 | Grok 4.2047.1 |
| Reasoning | DeepSeek V4 FlashNot measured | MarginNo overlap | Grok 4.2053.3 |
| Knowledge | DeepSeek V4 Flash38.8 | MarginNo overlap | Grok 4.20Not measured |
| Math | DeepSeek V4 Flash40.8 | MarginNo overlap | Grok 4.20Not measured |
| Multimodal | DeepSeek V4 FlashNot measured | MarginNo overlap | Grok 4.2070.1 |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
SWE-bench Verified
CodingA 73.7%B 76.7%Winner: Grok 4.20Δ 3SWE-bench Verified: DeepSeek V4 Flash scored 73.7%; Grok 4.20 scored 76.7%. Grok 4.20 wins this benchmark. - Source ↗
SWE-bench Pro
CodingA 49.1%B 51.8%Winner: Grok 4.20Δ 2.7SWE-bench Pro: DeepSeek V4 Flash scored 49.1%; Grok 4.20 scored 51.8%. Grok 4.20 wins this benchmark. - Source ↗
Terminal-Bench 2.0
AgenticA 49.1%B 47.1%Winner: DeepSeek V4 FlashΔ 2Terminal-Bench 2.0: DeepSeek V4 Flash scored 49.1%; Grok 4.20 scored 47.1%. DeepSeek V4 Flash wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | DeepSeek V4 Flash | Grok 4.20 | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | DeepSeek V4 Flash$0.14 input / $0.28 output | Grok 4.20$2 input / $6 output | DeepSeek V4 Flash has the lower combined listed price. |
| Generation speedtokens per second | DeepSeek V4 FlashNot available | Grok 4.20233 tok/s | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | DeepSeek V4 FlashNot available | Grok 4.2010.33 s | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | DeepSeek V4 Flash1M | Grok 4.202M | Grok 4.20 lists the larger context window. |
Benchmark Deep Dive
AgenticDeepSeek V4 Flash wins6 benchmarks
CodingGrok 4.20 wins6 benchmarks
| Benchmark | DeepSeek V4 Flash | Grok 4.20 | Result |
|---|---|---|---|
| SWE-bench VerifiedSource | 73.7% | 76.7% | Grok 4.20 leads |
| SWE-bench ProSource | 49.1% | 51.8% | Grok 4.20 leads |
| SWE MultilingualSource | 69.7% | — | Not comparable |
| Terminal-Bench 2.0Source | 49.1% | — | Not comparable |
| LiveCodeBench ProSource | — | 74.2% | Not comparable |
| Vibe Code BenchSource | — | 4.06% | Not comparable |
Reasoning3 benchmarks
Knowledge9 benchmarks
| Benchmark | DeepSeek V4 Flash | Grok 4.20 | Result |
|---|---|---|---|
| MMLU-ProSource | 83% | — | Not comparable |
| SimpleQASource | 23.1% | — | Not comparable |
| Chinese-SimpleQASource | 71.5% | — | Not comparable |
| GPQASource | 71.2% | — | Not comparable |
| GPQA-DSource | 71.2% | 88.5% | Grok 4.20 leads |
| HLESource | 8.1% | — | Not comparable |
| HLE w/o toolsSource | — | 31.6% | Not comparable |
| HealthBench HardSource | — | 20.3% | Not comparable |
| MedXpertQA (Text)Source | — | 50.2% | Not comparable |
Math4 benchmarks
Frequently Asked Questions (3)
Which is better, DeepSeek V4 Flash or Grok 4.20?
DeepSeek V4 Flash is ahead on BenchLM's BenchAlign leaderboard, 58.88 to 54.68. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 73.7% and 76.7%.
Which is better for coding, DeepSeek V4 Flash or Grok 4.20?
Grok 4.20 has the edge for coding in this comparison, averaging 67.1 versus 64.2. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.
Which is better for agentic tasks, DeepSeek V4 Flash or Grok 4.20?
DeepSeek V4 Flash has the edge for agentic tasks in this comparison, averaging 49.1 versus 47.1. Inside this category, Gert Labs is the benchmark that creates the most daylight between them.
Related Comparisons
Explore More
Choose a model with this week’s evidence
Join 2,000+ readers for ranking moves, pricing changes, and the claims that still need proof.
One email each week. Unsubscribe anytime.