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Gemini 3.5 Flash vs GPT-5.6 Sol

Compare Gemini 3.5 Flash and GPT-5.6 Sol side-by-side. See how these vision models stack up in Open Prompt, Image Captioning, OCR, Classification, and Object Detection.

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GoogleGemini 3.5 Flash
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OpenAIGPT-5.6 Sol
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Models in this comparison

Gemini 3.5 Flash vs GPT-5.6 Sol on Vision Evals

Gemini 3.5 Flash scores higher on all five Vision Evals tasks.

The widest gap is Reasoning, where Gemini 3.5 Flash leads 82.1% to 66.0%.

Overall, Gemini 3.5 Flash averages 81.8% (#4 of 63) against 72.4% (#18 of 63) for GPT-5.6 Sol.

Gemini 3.5 Flash is both cheaper ($0.012 vs $0.019 per sample) and faster (11.5s vs 12.2s per sample).

Gemini 3.5 FlashGPT-5.6 Sol

Gemini 3.5 Flash vs GPT-5.6 Sol Comparison Table

Evals updated October 13, 2026Pricing updated October 17, 2026

PropertyGemini 3.5 FlashGPT-5.6 Sol
OrganizationGoogleOpenAI
Categoryclosedclosed
Modalitymultimodalmultimodal
Release DateMay 2026Jul 2026
Context Window1.0M1.5M
ParametersUnknownUnknown
LicenseProprietaryProprietary
Commercial usecommercial use per vendor termscommercial use per vendor terms
Pricing per 1M tokens
Input $/1M$1.50$4.00
Output $/1M$9.00$20.00
Vision Tasks
CaptioningDemoDemo
Chart Question AnsweringSupportedSupported
ClassificationDemoDemo
Document Question AnsweringSupportedSupported
Image TaggingSupportedSupported
Multi-Label ClassificationSupportedSupported
Object DetectionDemoDemo
OCRDemoDemo
Vision LanguageSupportedSupported
Visual Question AnsweringDemoDemo
Model Features
Foundation VisionSupportedSupported
LLMs with Vision CapabilitiesSupportedSupported
Multimodal VisionSupportedSupported
Vision Evalsground-truth scores across 5 vision tasks, pooled at low effort
Overall
81.8%
72.4%
Avg cost / sample$0.012$0.019
Avg speed / sample11.52s12.16s
By task
Object Detection (low)
70.6%
±2.0, Mean of 3 runs, range 68.7 to 72.6
$0.016
68.4%
±0.7, Mean of 3 runs, range 67.9 to 69.3
$0.031
Object Detection (high)
69.8%
±1.8, Mean of 3 runs, range 67.5 to 71.1
$0.021
68.4%
±0.8, Mean of 3 runs, range 67.7 to 69.3
$0.071
Counting (low)
80.6%
±0.7, Mean of 3 runs, range 79.7 to 81.1
$0.0075
74.3%
±1.4, Mean of 3 runs, range 73.0 to 75.7
$0.0098
Counting (high)
82.4%
±0.0, Mean of 3 runs, range 82.4 to 82.4
$0.017
76.1%
±2.0, Mean of 3 runs, range 74.3 to 78.4
$0.016
Identification (low)
99.0%
±1.6, Mean of 3 runs, range 96.9 to 100.0
$0.0040
89.6%
±4.7, Mean of 3 runs, range 84.4 to 93.8
$0.0056
Identification (high)
97.9%
±1.6, Mean of 3 runs, range 96.9 to 100.0
$0.0068
92.7%
±1.6, Mean of 3 runs, range 90.6 to 93.8
$0.0060
OCR (low)
76.7%
$0.013
63.6%
$0.019
by category
Single value
71.7%
Transcription
90.0%
Structured JSON
86.8%
Text localization
56.2%
Single value
43.5%
Transcription
91.7%
Structured JSON
82.0%
Text localization
52.2%
OCR (high)
75.5%
$0.031
65.3%
$0.048
by category
Single value
69.6%
Transcription
85.4%
Structured JSON
88.1%
Text localization
53.3%
Single value
46.1%
Transcription
92.3%
Structured JSON
83.9%
Text localization
51.6%
Reasoning (low)
82.1%
±2.0, Mean of 3 runs, range 80.1 to 84.1
$0.0082
66.0%
±2.6, Mean of 3 runs, range 63.6 to 68.9
$0.0086
Reasoning (high)
81.0%
±1.7, Mean of 3 runs, range 79.5 to 82.8
$0.018
71.7%
±1.3, Mean of 3 runs, range 70.2 to 72.8
$0.012

Gemini 3.5 Flash vs GPT-5.6 Sol: Overview

Gemini 3.5 Flash

Gemini 3.5 Flash is a multimodal language model developed by Google DeepMind and released at Google I/O 2026. It is built on the Gemini 3 Flash reasoning foundation and introduces configurable thinking levels (minimal, low, medium, and high) that allow developers to tune the depth of internal reasoning before a response is generated. The model accepts text, image, video, audio, and PDF inputs and produces text output, with a 1 million token context window and up to 65,000 output tokens per request. It is natively multimodal, processing visual inputs alongside text to support tasks such as image captioning, classification, optical character recognition, object detection, and visual grounding, where the model references specific regions within an image or video frame.

Its vision capabilities extend to interpreting UI screenshots, diagrams, charts, and real-world scenes, as well as understanding video and live frame sequences for activity and scene recognition. The model supports combined tool use, including Google Search, URL context, code execution, and custom functions, within a single request, and it uses reasoning context from previous turns when thought signatures are present in the conversation history, enabling persistent multi-turn reasoning chains. Gemini 3.5 Flash carries a knowledge cutoff of January 2026 and is available via the Gemini API, Google AI Studio, Google Antigravity, and the Gemini Enterprise Agent Platform.

GPT-5.6 Sol

GPT-5.6 Sol is the flagship model in OpenAI's GPT-5.6 family, which also includes Terra (a balanced everyday-work tier) and Luna (a fast, cost-efficient tier). Sol is designed for demanding reasoning, long-horizon agentic workflows, software engineering, computer use, scientific research, and cybersecurity tasks. It introduces two new capability modes: a "max" reasoning effort setting that allocates additional compute time for difficult problems, and an "ultra" mode that coordinates multiple subagents in parallel to accelerate complex, multi-step work. The model supports native multimodal input, allowing it to process screenshots, diagrams, charts, documents, and photographs alongside text. A reported context window of approximately 1.5 million tokens enables processing of large codebases, lengthy research documents, and extended agentic sessions.

GPT-5.6 Sol was announced on June 26, 2026, initially in a limited preview for trusted partners, and reached general availability on July 9, 2026. On the Agents' Last Exam benchmark, which evaluates long-running professional workflows across 55 fields, Sol scores 53.6. On Terminal-Bench 2.1, which tests command-line agentic coding workflows, Sol Ultra achieves 91.9%. The model also demonstrates gains in life sciences evaluations, including long-horizon genomics and quantitative biology analyses. OpenAI paired the release with its most extensive safety evaluation to date, combining human red teaming with large-scale automated testing, and classified Sol as High capability in both cybersecurity and biological risk under its Preparedness Framework, though it does not cross the Critical threshold in either category.

Frequently Asked Questions

On Roboflow's Vision Evals, Gemini 3.5 Flash performed better. It scores higher on all five vision tasks and averages 81.8% (#4 of 63) against 72.4% (#18 of 63) for GPT-5.6 Sol. These scores measure vision capabilities only; either model may perform differently on work outside this benchmark's tasks.

Yes. On the Vision Evals Reasoning benchmark at low effort, Gemini 3.5 Flash leads with 82.1% against 66.0%. This is the widest gap between the two models across the benchmark's tasks.

Gemini 3.5 Flash is cheaper to run. Across Roboflow's Vision Evals task mix it averaged $0.012 per sample against $0.019. Gemini 3.5 Flash is priced at $1.50 per 1M input tokens and $9.00 per 1M output; GPT-5.6 Sol is priced at $4.00 per 1M input tokens and $20.00 per 1M output. Actual costs depend on your image sizes, prompts, and output length.

Gemini 3.5 Flash is faster. Across Roboflow's Vision Evals it averaged 11.5s per inference against 12.2s. 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 open prompts and image captioning in the free Roboflow Playground. You can try it instantly, and a free account unlocks unlimited runs.