Side-by-side comparison of pricing, 12 benchmarks, and generation speed.
| Metric | Grok 4.20 0309 v2 (Non-reasoning) | Gemini 3.5 Flash-Lite |
|---|---|---|
| Input ($/M tokens) | $1.25 | $0.3 |
| Output ($/M tokens) | $2.5 | $2.5 |
Verdict. Gemini 3.5 Flash-Lite takes the aggregate benchmark matchup 2–0 across 2 categories. Real workloads usually care about a handful of specific tasks — see the per-benchmark table above.
Pricing. Both models sit in the budget bracket for output-token pricing. At 1.0× the per-million-token cost, Gemini 3.5 Flash-Lite is meaningfully cheaper if your traffic is output-heavy (long completions, document generation, agent loops). Gemini 3.5 Flash-Lite makes more sense when output volume is low and absolute reasoning quality justifies the premium.
Strengths. Grok 4.20 0309 v2 (Non-reasoning) is strongest on Intelligence Index (22.2). Gemini 3.5 Flash-Lite leads on Coding Index (49.3), Intelligence Index (37.4).
Speed. On throughput, Gemini 3.5 Flash-Lite generates tokens at 332 tok/s versus 93 tok/s — about 72% faster. On time-to-first-token, Grok 4.20 0309 v2 (Non-reasoning) responds in 660ms vs 9760ms, which matters most for chat-style UIs.
Provider. SpaceXAI and Google sell to overlapping but distinct developer audiences: SpaceXAI tends to ship frontier reasoning models with premium positioning, while Google often prices more aggressively. Your existing vendor relationships, billing, and SLA preferences may matter as much as the raw numbers above.
Workload cost. Workload scenarios (per million requests at 30M input + 15M output tokens): Grok 4.20 0309 v2 (Non-reasoning) costs $75.00 ($900/year); Gemini 3.5 Flash-Lite costs $46.50 ($558/year). At a smaller 5M-input/2M-output scale (single-developer tool or prototype): Grok 4.20 0309 v2 (Non-reasoning) ≈ $11.25/run, Gemini 3.5 Flash-Lite ≈ $6.50/run. At agent/realtime scale (200M input / 100M output per million requests): Grok 4.20 0309 v2 (Non-reasoning) ≈ $500/run, Gemini 3.5 Flash-Lite ≈ $310/run. Gemini 3.5 Flash-Lite becomes more attractive at higher volume — the absolute per-token pricing difference compounds when you ship at scale.
Recommendation. Both models have legitimate use cases — the right answer depends on whether you are optimizing for benchmark ceiling, latency, or unit cost. Start with the cheaper / faster model, evaluate against your specific task, and only switch if the upgrade shows a meaningful lift.
Head-to-head deltas
Data from Artificial Analysis API — 12 benchmarks
Gemini 3.5 Flash-Lite is cheaper overall. Its blended price (3:1 input/output ratio) is $0.85/M tokens vs $1.56/M for Grok 4.20 0309 v2 (Non-reasoning).
Gemini 3.5 Flash-Lite wins 2 out of 12 benchmarks compared to 0 for Grok 4.20 0309 v2 (Non-reasoning). See the detailed benchmark chart above for per-category results.
Gemini 3.5 Flash-Lite generates tokens faster at 332 tok/s vs 93 tok/s. Grok 4.20 0309 v2 (Non-reasoning) also has lower time-to-first-token (0.66s vs 9.76s).
Choose based on your priorities: Gemini 3.5 Flash-Lite for lower cost, Gemini 3.5 Flash-Lite for stronger benchmark performance, and Gemini 3.5 Flash-Lite for faster generation. For latency-sensitive apps, check the TTFT comparison above.