Translate with OpenRouter
OpenRouter is an API gateway that gives you access to hundreds of AI models from multiple providers through a single API key. If you want flexibility to switch between models (or use models not directly supported in ButterKit), OpenRouter is the way to go.
Prerequisites
- A ButterKit Pro license
- An OpenRouter API key (create one at openrouter.ai/keys)
Connect OpenRouter to ButterKit
Open Settings
In ButterKit, go to Settings > Models.
Add a new model
Click the + button to add a new cloud model.
Enter your model details
Fill in the following fields:
| Field | Value |
|---|---|
| Description | OpenRouter (or any label you prefer) |
| URL | https://openrouter.ai/api |
| API Key | Your OpenRouter API key |
| Model | See popular models below |
| API Key Header | Leave blank (auto-detected) |
| Temperature | 0.35 |
Temperature controls randomness: lower values (0.0-0.3) produce more literal translations, while higher values (0.4-0.7) allow light paraphrasing. We recommend
0.35as a good starting point. Some endpoints may clamp or ignore this value.
Security: Your API key is stored securely in the macOS Keychain. It is never sent to ButterKit servers or any third party other than the provider you configure.
Connecting a cloud translation model in ButterKit Settings
Test the connection
Click Test Connection to verify that ButterKit can reach OpenRouter with your key. You should see a success confirmation.
Start translating
Toggle Use as default if you want OpenRouter for all translations, or select it from the Translate with dropdown when adding a localization.
Popular Models for Translation
OpenRouter provides access to models from many providers. Some well-suited options for translation:
| Model | Notes | Relative cost |
|---|---|---|
openai/gpt-4.1 | Strong instruction following, high-quality translations | Medium |
openai/gpt-4.1-mini | Great quality at lower cost | Low |
anthropic/claude-sonnet-4-6 | Nuanced, context-aware output | Medium |
anthropic/claude-haiku-4-5 | Fast and affordable | Low |
google/gemini-2.5-flash | Fast and cost-effective | Low |
google/gemini-2.5-pro | High-quality, deep reasoning | Medium |
meta-llama/llama-4-scout | Open-source, competitive quality | Low |
Browse the full catalog at openrouter.ai/models.
Why Use OpenRouter?
- One API key, many models. Switch between providers without managing separate accounts.
- Model comparison. Try different models to find the best fit for your language pairs.
- Cost flexibility. Choose budget-friendly models for bulk work and premium models for critical translations.
Billing
You are billed directly by OpenRouter based on per-token pricing that varies by model. ButterKit does not add any markup. Monitor your usage at openrouter.ai/activity.
Quick Help
- Need more help? Browse the Documentation
- Check out our Templates & Add-ons
- Join us on Discord for quick help
- Any other questions? Get in touch