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Gemini 3.1 Flash Image Preview vs Qwen3.5 Plus (OpenRouter): API Cost Comparison

Compare the API pricing, context windows, features, and real-world cost projections for Gemini 3.1 Flash Image Preview (Google) and Qwen3.5 Plus (OpenRouter) (OpenRouter). Use the interactive calculator below to compute your exact monthly cost based on your token usage and request volume.

Prices verified Mar 27, 2026

Interactive Cost Calculator

GoogleGemini 3.1 Flash Image PreviewOpenRouterQwen3.5 Plus (OpenRouter)

Fills in typical token counts for a workload type

Tokens in each prompt sent to the model

Tokens generated in each response

Total API calls per month

Showing costs for 2 models. Cheapest: Qwen3.5 Plus (OpenRouter) at $10.40/month.

Cheapest: Qwen3.5 Plus (OpenRouter) at $10.40/mo — save 48.0% vs Gemini 3.1 Flash Image Preview
Alert
BestQwen3.5 Plus (OpenRouter)
OpenRouter$10.40$0.001040$2.60$7.8048.0%Alerts coming soon
Gemini 3.1 Flash Image Preview
Google$20.00$0.002000$5.00$15.00Alerts coming soon

Monthly Cost Comparison

Price Comparison at a Glance

All prices are in USD per 1 million tokens ($/M tokens). Lower is cheaper.

Pricing TypeGemini 3.1 Flash Image PreviewQwen3.5 Plus (OpenRouter)Cheaper
Input (standard)$0.50/M$0.26/MQwen3.5 Plus (OpenRouter)
Output$3.00/M$1.56/MQwen3.5 Plus (OpenRouter)

Prices last verified: 2026-03-10 – 2026-03-27

Cost Breakdown by Usage Volume

Estimated monthly costs at different request volumes, assuming 1,000 input tokens and 500 output tokens per request. Adjust in the calculator above for your specific use case.

VolumeGemini 3.1 Flash Image PreviewMonthlyQwen3.5 Plus (OpenRouter)MonthlyGemini 3.1 Flash Image PreviewPer requestQwen3.5 Plus (OpenRouter)Per request
1K requests/mo$2.00$1.04$0.002000$0.001040
10K requests/mo$20.00$10.40$0.002000$0.001040
100K requests/mo$200.00$104.00$0.002000$0.001040
1M requests/mo$2,000.00$1,040.00$0.002000$0.001040

Green values indicate the lower-cost option at each volume tier. Cost per request is calculated at 1,000 input + 500 output tokens using standard (non-batch, non-cached) pricing.

Price History

Input price per 1M tokens

When to Choose Gemini 3.1 Flash Image Preview

by Google

  • General chatbot

Input / 1M tokens

$0.50/M

Output / 1M tokens

$3.00/M

Context window

65,536

Tier

budget

When to Choose Qwen3.5 Plus (OpenRouter)

by OpenRouter

  • Code generation
  • Document summarization
  • General chatbot

Input / 1M tokens

$0.26/M

Output / 1M tokens

$1.56/M

Context window

1,000,000

Tier

mid

Key Differences Beyond Price

Cost is only one factor in choosing an AI model. Context window size, rate limits, supported features, and latency all affect whether a model fits your use case.

CapabilityGemini 3.1 Flash Image PreviewQwen3.5 Plus (OpenRouter)
Context window65,536 tokens1,000,000 tokens
Max output tokens65,536 tokens65,536 tokens
Performance tierBudgetMid
Vision / image inputYesNo
Function callingYesYes
JSON modeYesYes
Prompt cachingNoNo
Batch API (50% discount)NoNo
Extended reasoningNoNo
Fine-tuningNoNo

Qwen3.5 Plus (OpenRouter) notes

OpenRouter offers 200+ models — showing top 15 unique models not available from other listed providers. Prices include OpenRouter markup.

Frequently Asked Questions

Is Gemini 3.1 Flash Image Preview cheaper than Qwen3.5 Plus (OpenRouter)?

At standard usage (1,000 input tokens, 500 output tokens, 100,000 requests/month), Qwen3.5 Plus (OpenRouter) costs $104.00/month versus $200.00/month for Gemini 3.1 Flash Image Preview — a 48% saving. Your actual savings will vary based on your token profile; output-heavy workloads amplify differences in output pricing.

Which model has a larger context window, Gemini 3.1 Flash Image Preview or Qwen3.5 Plus (OpenRouter)?

Qwen3.5 Plus (OpenRouter) has a larger context window at 1,000,000 tokens, compared to 65,536 tokens for Gemini 3.1 Flash Image Preview. A larger context window is important for processing long documents, multi-turn conversations, or large codebases without truncation.

Do Gemini 3.1 Flash Image Preview and Qwen3.5 Plus (OpenRouter) support the Batch API?

Neither Gemini 3.1 Flash Image Preview nor Qwen3.5 Plus (OpenRouter) currently supports a batch API with discounted pricing. For batch-eligible alternatives, consider models from OpenAI, Anthropic, or Google that include batch API support.

Which model offers better prompt caching?

Neither Gemini 3.1 Flash Image Preview nor Qwen3.5 Plus (OpenRouter) currently supports prompt caching. For prompt-caching capable alternatives, consider Claude models from Anthropic or GPT-4o from OpenAI.

What are the best use cases for Gemini 3.1 Flash Image Preview vs Qwen3.5 Plus (OpenRouter)?

Both models are well-suited for General chatbot. Gemini 3.1 Flash Image Preview is particularly strong for overlapping tasks. Qwen3.5 Plus (OpenRouter) is favored for Code generation, Document summarization. At the same quality level, the lower-cost model is usually preferable; use this page's calculator to compare total monthly spend at your volume.

What is the cost per request for Gemini 3.1 Flash Image Preview vs Qwen3.5 Plus (OpenRouter)?

At 1,000 input tokens and 500 output tokens per request — a typical conversational workload — Gemini 3.1 Flash Image Preview costs $0.002000 per request and Qwen3.5 Plus (OpenRouter) costs $0.001040 per request. At 100,000 requests/month, that translates to $200.00 and $104.00 respectively. Use the interactive calculator to adjust these parameters for your actual workload.

Gemini 3.1 Flash Image Preview vs Qwen3.5 Plus (OpenRouter): Summary

When comparing Gemini 3.1 Flash Image Preview and Qwen3.5 Plus (OpenRouter) for API cost, the right choice depends on your workload's token profile, required features, and tolerance for latency. Qwen3.5 Plus (OpenRouter) offers lower total cost at standard usage volumes (1,000 input + 500 output tokens per request at 100,000 requests/month) at $104.00/month, compared to $200.00/month for Gemini 3.1 Flash Image Preview.

Both models are priced in USD per million tokens, the standard unit across all major AI API providers. Gemini 3.1 Flash Image Preview charges $0.50/M for input tokens and $3.00/M for output tokens. Qwen3.5 Plus (OpenRouter) charges $0.26/M input and $1.56/M output. If your workload is output-heavy (more tokens generated than consumed as input), the model with the lower output price compounds cost savings significantly at scale.

Context window capacity differs between the two: Qwen3.5 Plus (OpenRouter) supports up to 1,000,000 tokens in a single request, versus 65,536 tokens for Gemini 3.1 Flash Image Preview. A larger context window is essential for document summarization, large codebase analysis, and multi-document retrieval-augmented generation (RAG) applications.

Use the interactive calculator at the top of this page to enter your actual token usage and monthly request volume for a precise cost comparison tailored to your workload. Adjust for batch API discounts and prompt caching to find the most cost-effective option for your specific deployment.

Explore other model comparisons from the same providers or performance tiers.

Related Provider Pages

View complete pricing tables and model lineups for the providers behind these models.

Relevant Use Cases

See cost recommendations for workloads where Gemini 3.1 Flash Image Preview or Qwen3.5 Plus (OpenRouter) is recommended.