Model comparison
Gemini 3.5 Flash-Lite vs Grok 4.20
Head-to-head evidence from 2 shared benchmark results across 2 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Gemini 3.5 Flash-Lite unranked (Not scored); Grok 4.20 #88 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Gemini 3.5 Flash-Lite and Grok 4.20 share 2 comparable benchmark results. 3 of 8 categories are comparable. 19 results are unique to Gemini 3.5 Flash-Lite; 16 to Grok 4.20.
Updated July 21, 2026- Shared results
- 2
- Gemini 3.5 Flash-Lite only
- 19
- Grok 4.20 only
- 16
- Comparable categories
- 3 / 8
Treat this as a split decision. Gemini 3.5 Flash-Lite makes more sense if reasoning is the priority or you want the cheaper token bill; Grok 4.20 is the better fit if coding is the priority or you need the larger 2M context window.
Confidence note. This is a partial-evidence comparison with 2 shared benchmark results across 2 evidence categories; 3 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
Gemini 3.5 Flash-Lite and Grok 4.20 finish on the same BenchAlign overall score, so this is less about a single winner and more about where the edge shows up. The BenchAlign headline says tie; the benchmark table is where the real choice happens.
Grok 4.20 is also the more expensive model on tokens at $2.00 input / $6.00 output per 1M tokens, versus $0.30 input / $2.50 output per 1M tokens for Gemini 3.5 Flash-Lite. That is roughly 2.4x on output cost alone. Grok 4.20 gives you the larger context window at 2M, compared with 1M for Gemini 3.5 Flash-Lite.
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 | Gemini 3.5 Flash-Lite | Δ | Grok 4.20 |
|---|---|---|---|
| Reasoning | Gemini 3.5 Flash-Lite72.2 | Margin← 18.9 | Grok 4.2053.3 |
| Agentic | Gemini 3.5 Flash-Lite63.4 | Margin← 16.3 | Grok 4.2047.1 |
| Coding | Gemini 3.5 Flash-Lite54.2 | Margin→ 12.9 | Grok 4.2067.1 |
| Multimodal | Gemini 3.5 Flash-LiteNot measured | MarginNo overlap | Grok 4.2070.1 |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
Terminal-Bench 2.0
AgenticA 54%B 47.1%Winner: Gemini 3.5 Flash-LiteΔ 6.9Terminal-Bench 2.0: Gemini 3.5 Flash-Lite scored 54%; Grok 4.20 scored 47.1%. Gemini 3.5 Flash-Lite wins this benchmark. - Source ↗
SWE-bench Pro
CodingA 54.2%B 51.8%Winner: Gemini 3.5 Flash-LiteΔ 2.4SWE-bench Pro: Gemini 3.5 Flash-Lite scored 54.2%; Grok 4.20 scored 51.8%. Gemini 3.5 Flash-Lite wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Gemini 3.5 Flash-Lite | Grok 4.20 | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Gemini 3.5 Flash-Lite$0.3 input / $2.5 output | Grok 4.20$2 input / $6 output | Gemini 3.5 Flash-Lite has the lower combined listed price. |
| Generation speedtokens per second | Gemini 3.5 Flash-LiteNot available | Grok 4.20233 tok/s | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Gemini 3.5 Flash-LiteNot available | Grok 4.2010.33 s | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Gemini 3.5 Flash-Lite1M | Grok 4.202M | Grok 4.20 lists the larger context window. |
Benchmark Deep Dive
AgenticGemini 3.5 Flash-Lite wins9 benchmarks
| Benchmark | Gemini 3.5 Flash-Lite | Grok 4.20 | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | 54% | 47.1% | Gemini 3.5 Flash-Lite leads |
| OSWorld-VerifiedSource | 74% | — | Not comparable |
| GDPval-AASource | 1140 | — | Not comparable |
| AA Agentic IndexSource | 26.8% | — | Not comparable |
| GDPval-AASource | 32.0% | — | Not comparable |
| AA BriefcaseSource | 634 | — | Not comparable |
| AA Tau3 BankingSource | 16.5% | — | Not comparable |
| DeepSearchQASource | — | 62.8% | Not comparable |
| Gert LabsSource | — | 38.36% | Not comparable |
CodingGrok 4.20 wins7 benchmarks
| Benchmark | Gemini 3.5 Flash-Lite | Grok 4.20 | Result |
|---|---|---|---|
| Terminal-Bench 2.0Source | 54.0% | — | Not comparable |
| SWE-bench ProSource | 54.2% | 51.8% | Gemini 3.5 Flash-Lite leads |
| AA Coding IndexSource | 49.3% | — | Not comparable |
| AA-SciCodeSource | 40.9% | — | Not comparable |
| LiveCodeBench ProSource | — | 74.2% | Not comparable |
| SWE-bench VerifiedSource | — | 76.7% | Not comparable |
| Vibe Code BenchSource | — | 4.06% | Not comparable |
ReasoningGemini 3.5 Flash-Lite wins4 benchmarks
Knowledge10 benchmarks
| Benchmark | Gemini 3.5 Flash-Lite | Grok 4.20 | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 36.5% | — | Not comparable |
| AA-GPQA DiamondSource | 83.8% | — | Not comparable |
| AA-HLESource | 17.5% | — | Not comparable |
| AA-Omniscience IndexSource | 6.9% | — | Not comparable |
| AA-Omniscience AccuracySource | 30.3% | — | Not comparable |
| AA-Omniscience Hallucination RateSource | 33.5% | — | Not comparable |
| GPQA-DSource | — | 88.5% | Not comparable |
| HLE w/o toolsSource | — | 31.6% | Not comparable |
| HealthBench HardSource | — | 20.3% | Not comparable |
| MedXpertQA (Text)Source | — | 50.2% | Not comparable |
Multimodal7 benchmarks
| Benchmark | Gemini 3.5 Flash-Lite | Grok 4.20 | Result |
|---|---|---|---|
| AA-MMMU-ProSource | 79.0% | — | Not comparable |
| MMMU-ProSource | — | 75.2% | Not comparable |
| CharXivSource | — | 60.9% | Not comparable |
| ERQASource | — | 54.1% | Not comparable |
| SimpleVQASource | — | 57.4% | Not comparable |
| MedXpertQA (MM)Source | — | 65.8% | Not comparable |
| Design Arena WebsiteSource | — | 1257 | Not comparable |
Frequently Asked Questions (4)
Which is better, Gemini 3.5 Flash-Lite or Grok 4.20?
Gemini 3.5 Flash-Lite and Grok 4.20 are tied on the BenchAlign overall score, so the right pick depends on which category matters most for your use case.
Which is better for coding, Gemini 3.5 Flash-Lite or Grok 4.20?
Grok 4.20 has the edge for coding in this comparison, averaging 67.1 versus 54.2. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.
Which is better for reasoning, Gemini 3.5 Flash-Lite or Grok 4.20?
Gemini 3.5 Flash-Lite has the edge for reasoning in this comparison, averaging 72.2 versus 53.3. Grok 4.20 stays close enough that the answer can still flip depending on your workload.
Which is better for agentic tasks, Gemini 3.5 Flash-Lite or Grok 4.20?
Gemini 3.5 Flash-Lite has the edge for agentic tasks in this comparison, averaging 63.4 versus 47.1. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.
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