Gemini 3 Flash Preview vs Grok 4.20 (Reasoning) vs Qwen3.8 27B
Gemini 3 Flash Preview comes out ahead, 72 to 67 and 66 on our weighted score, though Qwen3.8 27B is 17% cheaper per token.
- Our pick
GoogleGemini 3 Flash Preview
72/100- ECI152.0
- Price$0.50 / $3.00
- Context1.05M
xAIGrok 4.20 (Reasoning)
67/100- ECI152.3
- Price$1.25 / $2.50
- Context1M
Alibaba (Qwen)Qwen3.8 27B
66/100- ECI151.8
- Price$0.40 / $2.55
- Context262K
Gemini 3 Flash Preview is our pick
Gemini 3 Flash Preview is the better all-round choice, scoring 72/100 against Grok 4.20 (Reasoning) (67) and Qwen3.8 27B (66). It leads on inputs & features. Qwen3.8 27B wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
- CapabilityGrok 4.20 (Reasoning)Capabilities Index (ECI): Grok 4.20 (Reasoning) 152.3 · Gemini 3 Flash Preview 152.0 · Qwen3.8 27B 151.8
- Lowest priceQwen3.8 27BQwen3.8 27B $0.938 · Gemini 3 Flash Preview $1.13 · Grok 4.20 (Reasoning) $1.56 per 1M tokens (3:1 blend)
- Longest contextGemini 3 Flash PreviewGemini 3 Flash Preview 1,048,576 · Grok 4.20 (Reasoning) 1,000,000 · Qwen3.8 27B 262,144 tokens
- Widest inputsGemini 3 Flash PreviewGemini 3 Flash Preview: Text, Images, PDFs, Audio, Video · Grok 4.20 (Reasoning): Text, Images, PDFs · Qwen3.8 27B: Text, Images, Video
- Self-hostingQwen3.8 27BPublishes downloadable weights
| Measure | Weight | Gemini 3 Flash Preview | Grok 4.20 (Reasoning) | Qwen3.8 27B |
|---|---|---|---|---|
| CapabilityCapabilities Index (ECI) | 50% | 79 | 79 | 79 |
| Price | 25% | 45 | 39 | 49 |
| Inputs & features | 15% | 100 | 80 | 70 |
| Context window | 10% | 61 | 60 | 37 |
| Overall | 100% | 72/100 | 67/100 | 66/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Gemini 3 Flash PreviewGoogle | Grok 4.20 (Reasoning)xAI | Qwen3.8 27BAlibaba (Qwen) |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | 152.0 | 152.3 (best) | 151.8 |
| ECI rank | #53 of 165 | #51 of 165 (best) | #54 of 165 |
| GPQA DiamondGraduate-level science questions | 89.4% (best) | 89.3% | — |
| FrontierMath Tiers 1–3Research-level mathematics | 51.2% (best) | 44.9% | — |
| OTIS Mock AIME 2024–2025Competition mathematics | 95.6% (best) | 92.2% | — |
| SWE-bench VerifiedFixing real GitHub issues | 75.4% | — | — |
| SimpleQA VerifiedShort factual questions | 66.8% (best) | 30.2% | — |
| Price per million tokens | |||
| Input | $0.50 | $1.25 | $0.40 (best) |
| Output | $3.00 | $2.50 (best) | $2.55 |
| Cached input | $0.05 (best) | $0.20 | — |
| Blended (3:1) | $1.13 | $1.56 | $0.938 (best) |
| Long-context rate | Same rate | Over 200K: $2.50 / $5.00 | Same rate |
| Price source | Official Google API | Official xAI API | Median of 49 providers |
| Limits | |||
| Context window | 1,048,576 tokens (best) | 1,000,000 tokens | 262,144 tokens |
| Max output | 65,536 tokens (best) | 30,000 tokens | 32,768 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | Yes | Yes |
| PDFs | Yes | Yes | No |
| Audio | Yes | No | No |
| Video | Yes | No | Yes |
| Reasoning | Yesminimal · low · medium · high | Yes | Yes |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | Yes | No |
| Availability | |||
| Weights | Proprietary | Proprietary | Open |
| API model ID | gemini-3-flash-preview | grok-4.20-0309-reasoning | — |
| API providers | 31 | 15 | 53 (best) |
| Released | Dec 17, 2025 | Mar 9, 2026 | Aug 14, 2026 |
| Knowledge cutoff | Jan 2025 | — | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Gemini 3 Flash Preview$11.00
- Grok 4.20 (Reasoning)$17.50
- Qwen3.8 27B$9.10
Which should you choose?
Which is better: Gemini 3 Flash Preview, Grok 4.20 (Reasoning) or Qwen3.8 27B?
Gemini 3 Flash Preview is the better all-round choice, scoring 72/100 against Grok 4.20 (Reasoning) (67) and Qwen3.8 27B (66). It leads on inputs & features. Qwen3.8 27B wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.
Which is cheaper, Gemini 3 Flash Preview, Grok 4.20 (Reasoning) or Qwen3.8 27B?
Qwen3.8 27B is cheaper at $0.40 input / $2.55 output per million tokens (median across 49 API providers). Gemini 3 Flash Preview costs $0.50 input / $3.00 output per million tokens (official Google API price); Grok 4.20 (Reasoning) costs $1.25 input / $2.50 output per million tokens (official xAI API price). At a typical mix of three input tokens to one output token, that is $0.938 per million tokens for Qwen3.8 27B versus $1.13 for Gemini 3 Flash Preview (1.2× as much) and $1.56 for Grok 4.20 (Reasoning) (1.7× as much).
Which scores higher on benchmarks?
Grok 4.20 (Reasoning) scores higher on the Capabilities Index (ECI): Grok 4.20 (Reasoning) 152.3 (#51 of 165), Gemini 3 Flash Preview 152.0 (#53 of 165) and Qwen3.8 27B 151.8 (#54 of 165). The confidence ranges of the top two overlap (149.5–154.7 vs 150.6–153.7), so treat the gap as small.
Which is better for coding?
There are no published SWE-bench Verified results for Grok 4.20 (Reasoning) and Qwen3.8 27B yet, so there is no like-for-like coding score. On overall capability, Grok 4.20 (Reasoning) leads, which tends to carry over to coding, but test on your own codebase. All three support tool calling for agent workflows.
Which has the bigger context window?
Gemini 3 Flash Preview has the largest context window at 1,048,576 tokens, against 1,000,000 for Grok 4.20 (Reasoning) and 262,144 for Qwen3.8 27B. Maximum output per response: Gemini 3 Flash Preview up to 65,536, Grok 4.20 (Reasoning) up to 30,000, Qwen3.8 27B up to 32,768 tokens.
Which can read images, PDFs, audio or video?
Gemini 3 Flash Preview accepts text, images, PDFs, audio and video; Grok 4.20 (Reasoning) accepts text, images and PDFs; Qwen3.8 27B accepts text, images and video. Gemini 3 Flash Preview handles the widest range of inputs.
Are any of these open source?
Qwen3.8 27B publishes its weights and can be self-hosted; Gemini 3 Flash Preview and Grok 4.20 (Reasoning) is proprietary.
Which is newer?
Qwen3.8 27B is the newest, released Aug 14, 2026. Grok 4.20 (Reasoning) came out Mar 9, 2026; Gemini 3 Flash Preview came out Dec 17, 2025. Knowledge cutoff: Gemini 3 Flash Preview Jan 2025.
How do you decide the winner?
Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Nov 2, 2026.
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