Gemini 3.8 Flash vs Gemini 4 Hydrogen
Gemini 4 Hydrogen and Gemini 3.8 Flash score 87.3% vs 79.8% averaged across five Vision Evals tasks (#3 and #11 of 69 models), so Gemini 4 Hydrogen leads overall.
- Gemini 4 Hydrogen wins 4 of the 5 tasks, with its widest lead on OCR (86.7% vs 72.8%).
- Gemini 3.8 Flash is about half the cost: $0.0045 vs $0.0094 overall average cost per sample.
Roboflow Vision Evals. Full breakdown below.
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Gemini 3.8 Flash vs Gemini 4 Hydrogen on Vision Evals
Roboflow Vision Evals. Full breakdown below.
Gemini 3.8 Flash vs Gemini 4 Hydrogen Comparison Table
Evals updated November 12, 2026Pricing updated November 13, 2026
| Property | Gemini 3.8 Flash | Gemini 4 Hydrogen |
|---|---|---|
| Organization | ||
| Category | closed | closed |
| Modality | multimodal | multimodal |
| Release Date | Sep 2026 | Nov 2026 |
| Context Window | 1.0M | 1.0M |
| Parameters | Unknown | Unknown |
| License | Proprietary | Proprietary |
| Commercial use | commercial use per vendor terms | commercial use per vendor terms |
| Pricing per 1M tokens | ||
| Input $/1M | $0.825 | No published price |
| Output $/1M | $4.13 | No published price |
| Vision Tasks | ||
| Chart Question Answering | Supported | Not listed |
| Document Question Answering | Supported | Not listed |
| Image Tagging | Supported | Not listed |
| Multi-Label Classification | Supported | Not listed |
| Promptable Concept Segmentation | Not listed | Demo |
Both support 6 more tasks | ||
| Model Features | ||
Both support 3 more features | ||
Vision Evalsground-truth scores across 5 vision tasks, pooled at low effort | ||
| Overall | 79.8% | 87.3% |
| Avg cost / sample | $0.0045 | $0.0094 |
| Avg speed / sample | 12.76s | 13.23s |
| By task | ||
| Object Detection (low) | 68.1% ±0.8, Mean of 3 runs, range 67.3 to 69.0 | 81.0% ±0.8, Mean of 3 runs, range 80.3 to 81.9 |
| Object Detection (high) | 74.8% ±1.1, Mean of 3 runs, range 73.4 to 75.6 | 83.3% ±0.7, Mean of 3 runs, range 82.4 to 83.8 |
| Counting (low) | 78.8% ±2.7, Mean of 3 runs, range 75.7 to 81.1 | 83.8% ±2.0, Mean of 3 runs, range 82.4 to 86.5 |
| Counting (high) | 79.3% ±1.4, Mean of 3 runs, range 78.4 to 81.1 | 84.2% ±2.7, Mean of 3 runs, range 82.4 to 87.8 |
| Identification (low) | 97.9% ±1.6, Mean of 3 runs, range 96.9 to 100.0 | 96.9% ±0.0, Mean of 3 runs, range 96.9 to 96.9 |
| Identification (high) | 96.9% ±0.0, Mean of 3 runs, range 96.9 to 96.9 | 96.9% ±0.0, Mean of 3 runs, range 96.9 to 96.9 |
| OCR (low) | 72.8% | 86.7% |
| by category |
|
|
| OCR (high) | 78.7% | 87.2% |
| by category |
|
|
| Reasoning (low) | 81.2% ±0.3, Mean of 3 runs, range 80.8 to 81.5 | 88.1% ±0.7, Mean of 3 runs, range 87.4 to 88.7 |
| Reasoning (high) | 84.5% ±1.0, Mean of 3 runs, range 83.4 to 85.4 | 91.8% ±0.3, Mean of 3 runs, range 91.4 to 92.0 |
Gemini 3.8 Flash vs Gemini 4 Hydrogen: Overview
Gemini 3.8 Flash is a natively multimodal reasoning model in Google's Gemini 3 series, positioned as the speed and cost oriented Flash tier while targeting long-horizon software engineering, autonomous agents, and enterprise workflows. It accepts text, images, video, audio, and PDF documents in a single request and returns text, with an input limit of 1,048,576 tokens and an output limit of 65,536 tokens. Thinking is configurable at low, medium, and high levels, and the model supports function calling, code execution, structured outputs, context caching, search and Maps grounding, file search, and computer use in preview. Image generation, audio generation, and the Live API are not supported.
Following Gemini API conventions, it can localize objects by emitting bounding boxes as [ymin, xmin, ymax, xmax] integers normalized to a 0 to 1000 range, which supports prompt driven detection and grounding in addition to captioning, document parsing, and visual question answering. The knowledge cutoff is March 2026, though coverage in some domains reflects the January 2025 cutoff shared across the Gemini 3 family.
Gemini 4 Hydrogen is a multimodal model from Google, positioned as a successor to Gemini 3.8 Flash with stronger agent and coding capabilities at Flash-class speed.
Frequently Asked Questions
On Roboflow's Vision Evals, Gemini 4 Hydrogen performed better. It scores higher on 4 of the five vision tasks and averages 87.3% (#3 of 69) against 79.8% (#11 of 69) for Gemini 3.8 Flash. These scores measure vision capabilities only; either model may perform differently on work outside this benchmark's tasks.
No. On the Vision Evals OCR benchmark at low effort, Gemini 4 Hydrogen leads with 86.7% against 72.8%. This is the widest gap between the two models across the benchmark's tasks.
Gemini 3.8 Flash is cheaper to run. Across Roboflow's Vision Evals task mix it averaged $0.0045 per sample against $0.0094. Actual costs depend on your image sizes, prompts, and output length.
Gemini 3.8 Flash is faster. Across Roboflow's Vision Evals it averaged 12.8s per inference against 13.2s. Latency varies with image size, prompt length, and provider load, so treat these as relative rather than guaranteed figures.
Yes. The comparison demo on this page runs both models on the same image side by side for object detection and image captioning in the free Roboflow Playground. You can try it instantly, and a free account unlocks unlimited runs.