About 5 min read

Model Selection Guide

Karma One integrates seven frontier AI models from five providers, giving you the flexibility to choose the right intelligence for every task. This guide explains each model's strengths, costs, and ideal use cases.

Available Models

Claude Sonnet 4 — The Daily Driver

| Property | Value | |---|---| | Provider | Anthropic | | Context window | 200K tokens | | Speed | Fast | | Energy cost | Medium | | Best for | Writing, analysis, coding, general tasks |

Claude Sonnet 4 is the recommended default for most users. It delivers strong performance across writing, reasoning, coding, and conversation at a reasonable energy cost. If you are unsure which model to pick, start here.

Strengths:

  • Excellent at following nuanced instructions
  • Strong writing quality with natural tone
  • Reliable code generation across languages
  • Good balance of speed, quality, and cost

Example tasks:

Rewrite this email to sound more professional but keep it concise.

Review this Python function and suggest improvements for readability and performance.

Claude Opus 4 — The Deep Thinker

| Property | Value | |---|---| | Provider | Anthropic | | Context window | 200K tokens | | Speed | Moderate | | Energy cost | High | | Best for | Complex coding, research, deep analysis |

Claude Opus 4 is the most capable reasoning model in the lineup. Use it when you need thorough analysis, multi-step problem solving, or production-quality code. It costs more energy per message but produces noticeably better results on hard problems.

Strengths:

  • Superior reasoning on complex, multi-step tasks
  • Best code generation quality (architecture, debugging, refactoring)
  • Deep analytical writing (research reports, technical documentation)
  • Handles ambiguous or open-ended requests with more nuance

Example tasks:

Design a microservices architecture for an e-commerce platform handling 10M daily active users. Include database choices, caching strategy, and message queue design.

Analyze the root cause of this intermittent test failure. Here is the test file, the source code, and the CI logs from the last 5 runs.

Tip: Save Opus for tasks where quality matters more than speed. For quick questions, Sonnet is usually sufficient and costs less energy.

Gemini 2.5 Pro — The Multimodal Expert

| Property | Value | |---|---| | Provider | Google | | Context window | 1M tokens | | Speed | Moderate | | Energy cost | Medium-High | | Best for | Image/video analysis, long documents, multimodal tasks |

Gemini 2.5 Pro excels at understanding visual content and processing extremely long documents. Its 1 million token context window means you can feed entire codebases or book-length documents in a single conversation.

Strengths:

  • Best-in-class image understanding
  • Video content analysis
  • 1M token context for massive documents
  • Native multimodal reasoning (text + images together)

Example tasks:

[Upload a chart image] Analyze this quarterly revenue chart. What are the key trends and anomalies?

[Upload a 200-page PDF] Summarize the key findings from this research paper and list all cited methodologies.

Gemini 2.5 Flash — The Speed Champion

| Property | Value | |---|---| | Provider | Google | | Context window | 1M tokens | | Speed | Fastest | | Energy cost | Low | | Best for | Quick answers, summaries, simple tasks |

Gemini 2.5 Flash is the fastest model available. It provides good-enough quality for straightforward tasks at the lowest energy cost. Use it for high-volume, low-complexity work.

Strengths:

  • Sub-second response times for simple queries
  • Lowest energy consumption per message
  • Still supports multimodal input (images, files)
  • 1M token context window despite the low cost

Example tasks:

What is the capital of Uruguay?

Convert this JSON to a markdown table.

Qwen3 — The Chinese Language Specialist

| Property | Value | |---|---| | Provider | Alibaba Cloud | | Context window | 128K tokens | | Speed | Fast | | Energy cost | Low | | Best for | Chinese writing, translation, bilingual work |

Qwen3 delivers the best Chinese language experience. If your work involves Chinese content creation, Chinese-English translation, or understanding Chinese cultural context, Qwen3 should be your first choice.

Strengths:

  • Superior Chinese text generation (natural, idiomatic phrasing)
  • Excellent Chinese-English and Chinese-Japanese translation
  • Deep understanding of Chinese idioms, culture, and business conventions
  • Strong performance on Chinese standardized test benchmarks

Example tasks:

将以下英文产品说明翻译为适合中国市场的营销文案，注意语气要亲和专业。

Write a formal business email in Chinese to a potential partner in Shenzhen. The tone should be respectful but forward-looking.

GLM-4-Plus — Search-Augmented Chinese AI

| Property | Value | |---|---| | Provider | Zhipu AI | | Context window | 128K tokens | | Speed | Moderate | | Energy cost | Medium | | Best for | Chinese tasks requiring current information |

GLM-4-Plus combines strong Chinese language ability with built-in web search. When your question requires up-to-date information, especially about Chinese markets, regulations, or news, GLM-4-Plus can fetch and synthesize real-time data.

Strengths:

  • Built-in web search (no separate tool call needed)
  • Current information about Chinese markets and policy
  • Good at synthesizing search results into coherent answers
  • Handles Chinese legal and regulatory questions well

Example tasks:

最新的中国个人所得税起征点是多少？有哪些专项附加扣除？

Search for the latest AI regulations published by the CAC this month and summarize the key requirements.

DeepSeek-R1 — The Reasoning Engine

| Property | Value | |---|---| | Provider | DeepSeek | | Context window | 128K tokens | | Speed | Slow (thinks step-by-step) | | Energy cost | Medium | | Best for | Math, logic, step-by-step reasoning |

DeepSeek-R1 is a reasoning-focused model that shows its work. It excels at mathematical problems, logical puzzles, and any task where transparent step-by-step thinking adds value. Responses are slower because the model explicitly works through its reasoning chain.

Strengths:

  • Visible chain-of-thought reasoning
  • Strong mathematical problem solving
  • Excellent at logic puzzles and formal reasoning
  • Good at tasks requiring systematic, verifiable steps

Example tasks:

Prove that the square root of 2 is irrational using proof by contradiction.

A factory produces 3 types of widgets. Type A takes 2 hours and yields $50 profit. Type B takes 3 hours and yields $70. Type C takes 1.5 hours and yields $30. The factory runs 16 hours per day. Find the optimal production mix to maximize daily profit.

Model Comparison Table

| Model | Speed | Reasoning | Chinese | Multimodal | Cost | Context | |---|---|---|---|---|---|---| | Claude Sonnet 4 | Fast | Strong | Good | Yes | Medium | 200K | | Claude Opus 4 | Moderate | Best | Good | Yes | High | 200K | | Gemini 2.5 Pro | Moderate | Strong | Good | Best | Medium-High | 1M | | Gemini 2.5 Flash | Fastest | Basic | Good | Yes | Low | 1M | | Qwen3 | Fast | Good | Best | Yes | Low | 128K | | GLM-4-Plus | Moderate | Good | Strong | Yes | Medium | 128K | | DeepSeek-R1 | Slow | Deep | Good | Limited | Medium | 128K |

Scenario-Based Recommendations

| Scenario | Recommended Model | Why | |---|---|---| | Quick factual question | Gemini 2.5 Flash | Fastest, cheapest | | Write a blog post | Claude Sonnet 4 | Best writing quality per energy | | Debug production code | Claude Opus 4 | Deepest code reasoning | | Analyze a chart image | Gemini 2.5 Pro | Best visual understanding | | Chinese marketing copy | Qwen3 | Most natural Chinese | | Current Chinese regulations | GLM-4-Plus | Built-in search | | Solve a math proof | DeepSeek-R1 | Transparent reasoning chain | | Analyze a 500-page PDF | Gemini 2.5 Pro | 1M context window | | Casual conversation | Gemini 2.5 Flash | Low cost, fast | | System architecture design | Claude Opus 4 | Complex reasoning |

How to Switch Models

Per-Conversation

  1. Open a conversation.
  2. Tap the model name displayed at the top of the chat.
  3. Select a different model from the dropdown.
  4. All subsequent messages in this conversation will use the new model.

Smart Select Mode

Enable Smart Select in settings to let Karma One automatically choose the best model for each message based on content analysis:

  • Detects language and routes Chinese-heavy requests to Qwen3 or GLM-4-Plus
  • Routes image-heavy requests to Gemini 2.5 Pro
  • Uses Flash for simple lookups and Sonnet for general tasks
  • Escalates complex reasoning requests to Opus or DeepSeek-R1

Tip: Smart Select works well for users who switch between different types of tasks throughout the day. Power users who know exactly what they need may prefer manual selection.

Energy Cost Reference

Each model consumes different amounts of energy per message. Actual cost varies by message length and complexity.

| Model | Approximate Energy per Message | |---|---| | Gemini 2.5 Flash | 1-2 | | Qwen3 | 1-3 | | Claude Sonnet 4 | 3-5 | | GLM-4-Plus | 3-5 | | DeepSeek-R1 | 3-6 | | Gemini 2.5 Pro | 4-7 | | Claude Opus 4 | 8-15 |

See Subscription Plans for details on daily energy allowances by plan tier.