Gemini 3.8 Flash vs Grok 4.5
At a Glance
| Compare |  Gemini 3.8 FlashGoogle DeepMind | Grok 4.5xAI |
|---|---|---|
| Intelligence, Cost, and Efficiency | ||
| IntelligenceHigher is better · MM Intelligence v2.5 | #8 of 4682.0 score · 2/3 sources · provisional · missing ARC-AGI-2 · full-core range 54.7–88.0 | #25 of 4660.1 score · 3/3 sources · complete |
| CostLower is better · Published-token output estimate | #26 of 44$0.160 per LiveBench case | #15 of 44$0.063 per LiveBench case |
| EfficiencyHigher is better · MM Efficiency v1.5 | #8 of 3860.4 score · 2/3 sources · provisional · missing ARC-AGI-2 · full-core range 46.7–63.4 | #11 of 3859.2 score · 3/3 sources · complete |
| Pricing and Limits | ||
| Input priceFrom · USD / 1M tokens | $0.75Google AI ↗ · Sep 2, 2026 | $2.00Xai ↗ · Sep 3, 2026 |
| Output priceFrom · USD / 1M tokens | $3.75Google AI ↗ · Sep 2, 2026 | $6.00Xai ↗ · Sep 3, 2026 |
| Context windowMaximum documented tokens | 1,049K | 500K |
| Model facts checked | Sep 2, 2026View model evidence → | Sep 3, 2026View model evidence → |
Token prices are the lowest available sourced USD rates; input and output may use different providers. Cost ranking estimates output spend on LiveBench, not a full request bill. Ranking methodology →
Available Benchmarks
| Benchmark | Gemini 3.8 Flash | Grok 4.5 |
|---|---|---|
| LMArena Agent Arenaagent-2026-09-15-d25aabda0010 · outcome_score · statistical tie | 4.71100% of row best · score · Gemini 3.8 Flash (High); 95% CI [2.80246501, 6.61533867]; sessions 12534; observations 712246; rank 13 | 2.9298% of row best · score · Grok 4.5; 95% CI [1.93207740, 3.90928463]; sessions 38146; observations 1942877; rank 19 |
| LMArena Text Arenatext-2026-09-13-d25aabda0010 · arena_rating · leader | 1,494.67100% of row best · rating · gemini-3.8-flash-high; 95% CI [1486.13928353, 1503.20869643]; votes 5076; rank 6 | 1,450.1397% of row best · rating · grok-4.5; 95% CI [1445.44268767, 1454.81726995]; votes 30103; rank 45 |
| LiveBench2026-06-25 · overall · leader | 80.85100% of row best · percent · gemini-3.8-flash-high · 42,786 output tokens / case | 80.0199% of row best · percent · grok-4.5 · 10,517 output tokens / case |
| ToneBench2026-09-11-10-task-4ef099199c9c · overall_score · unverified | 77.8295% of row best · points · Gemini 3.8 Flash (high thinking) · 13,616 output tokens / case | 82.23100% of row best · points · Grok 4.5 · 2,688 output tokens / case |
| Overall ResultCounted from the protocol-matched rows above · 1 tie | 2 benchmark winsOverall lead | 0 benchmark wins |
Third-party benchmark Only like-for-like primary-publisher results are shown; raw scores, relative scores, configuration, and token spend remain visible.
Side-by-Side Facts
| Field | Gemini 3.8 Flash | Grok 4.5 |
|---|---|---|
| Developer | Google DeepMind | xAI |
| Family | Gemini 3 | Grok 4 |
| Model | Gemini 3.8 Flash | Grok 4.5 |
| Version | Gemini 3.8 Flash | Grok 4.5 |
| Lifecycle | active | active |
| Released | 2026-09-02 | 2026-07-16 |
| Knowledge cutoff | Unknown | Unknown |
| Input modalities | Text, Image, Video, Audio, Document | Text, Image |
| Output modalities | Text | Text |
| Context window | 1,049K | 500K |
| Total parameters | Unknown | Unknown |
| Active parameters | Unknown | Unknown |
| License | Unknown | Unknown |
| Open weights | No | No |
| API available | Yes | Yes |
| Self-hostable | No | No |
| Provider access | Google AI (Standard), Google Gemini (Standard) | Xai (Standard) |
| Capabilities | chat, code_execution, computer_use, generation, reasoning, structured_outputs, tools | chat, generation, reasoning, structured_outputs, tools |
Gemini 3.8 Flash Capabilities
Grok 4.5 Capabilities
Related Comparisons
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|---|---|---|---|
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Gemini 3.8 FlashGoogle DeepMind | vs | Grok 4.6xAI | cross-developer peerstext |
Gemini 3.8 FlashGoogle DeepMind | vs |  Qwen3.8-MaxQwen | cross-developer peerstext |
Gemini 3.8 FlashGoogle DeepMind | vs |  Kimi-K3Moonshot AI | cross-developer peerstext |
 MiniMax-M3MiniMax | vs | Gemini 3.8 FlashGoogle DeepMind | cross-developer peerstext |
Gemini 3.8 FlashGoogle DeepMind | vs |  GLM-5.3Z.ai | cross-developer peerstext |
Gemini 3.8 FlashGoogle DeepMind | vs |  Hy4 previewTencent | cross-developer peerstext |
Seed 2.1 ProByteDance Seed | vs | Gemini 3.8 FlashGoogle DeepMind | cross-developer peerstext |
Primary Evidence
Sources and Freshness
Questions
Gemini 3.8 Flash vs Grok 4.5 FAQs
Is Gemini 3.8 Flash or Grok 4.5 better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both Gemini 3.8 Flash and Grok 4.5, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, Gemini 3.8 Flash or Grok 4.5?+
Gemini 3.8 Flash is $0.75 and Grok 4.5 is $2.00 per million tokens, so Gemini 3.8 Flash is cheaper on this metric. Gemini 3.8 Flash is $3.75 and Grok 4.5 is $6.00 per million tokens, so Gemini 3.8 Flash is cheaper on this metric.
Which has a larger context window, Gemini 3.8 Flash or Grok 4.5?+
Gemini 3.8 Flash has the larger sourced context window. Gemini 3.8 Flash supports 1,049K and Grok 4.5 supports 500K.
Which performs better in benchmarks, Gemini 3.8 Flash or Grok 4.5?+
Gemini 3.8 Flash leads the current overall benchmark count. The result uses 3 protocol-matched benchmarks from 2 publishers; it is not a universal quality score.
Can Gemini 3.8 Flash or Grok 4.5 be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. Gemini 3.8 Flash is not marked open weight; Grok 4.5 is not marked open weight.
Can Gemini 3.8 Flash and Grok 4.5 understand images?+
Gemini 3.8 Flash is documented with image input; Grok 4.5 is documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, Gemini 3.8 Flash or Grok 4.5?+
Neither has a larger sourced maximum output. Gemini 3.8 Flash is 66K and Grok 4.5 is —.
Do Gemini 3.8 Flash and Grok 4.5 support reasoning and tool use?+
Gemini 3.8 Flash: reasoning, tool calling, and image input. Grok 4.5: reasoning, tool calling, and image input. Feature support does not establish relative quality.
Which is available from more inference providers, Gemini 3.8 Flash or Grok 4.5?+
Gemini 3.8 Flash has 2 sourced provider routes; Grok 4.5 has 1, so Gemini 3.8 Flash has broader tracked availability.
Which offers better value, Gemini 3.8 Flash or Grok 4.5?+
There is no universal value winner. Compare the input and output prices above with the matched benchmark result for your workload: cheaper tokens can be offset by different quality, token usage, latency, or provider availability.