How to Translate with a Local LLM (Ollama, LM Studio, Jan)

StringLane's Local LLM (OpenAI-compatible) provider lets you translate without sending data to any cloud. It works with any inference runner that exposes an OpenAI-compatible HTTP API: Ollama, LM Studio, Jan, llama.cpp, vLLM.

Why local#

• No API key, no per-token billing.
• No network egress. Your strings stay on the machine.
• No rate limits beyond your hardware.
• Smaller models (Llama 3.2, Qwen 2.5, Mistral 7B) are good enough for translation tasks when paired with StringLane's locale-aware prompts.

Step 1: Run a local model server#

Pick whichever runner you already have:

Runner	Default base URL	How to install
Ollama	http://localhost:11434/v1	brew install ollama && ollama pull llama3.2
LM Studio	http://localhost:1234/v1	Download the desktop app, load a model, click "Start Server"
Jan	http://localhost:1337/v1	Download the desktop app, enable the "Local API Server"
llama.cpp	varies	./llama-server -m model.gguf --port 8080

Start the server, pull/load a model, and confirm you can curl the /v1/models endpoint.

Step 2: Configure StringLane#

Open Settings → App → AI Providers (or run "Open Settings" from the Command Palette).

1. Provider: pick Local LLM (OpenAI-compatible).
2. Base URL: enter your runner's URL. Default is http://localhost:11434/v1 (Ollama). Adjust per the table above.
3. Model: type the exact model name your runner has loaded (e.g. llama3.2, qwen2.5:14b, mistral).
4. No API key field appears: local runners typically don't authenticate.

Save and close Settings.

Step 3: Translate#

Use the same flows you would with a cloud provider:

• Per-cell ✨ button on a Missing or Same row.
• ⌘T: translate the active key into every non-base locale.
• ⌘⇧T: translate (or re-translate) only the focused locale's field, leaving the key's other locales untouched.
• Translate all missing with AI from the Command Palette: sweeps every gap across every locale.
• Fix all with AI in the Issues Panel: repairs ICU and placeholder errors in place.

StringLane's prompts already include CLDR plural rules, locale formality / honorifics, format-specific placeholder dialects, and a glossary of recurring terms. Those are sent regardless of provider, so a local model gets the same context a cloud model does.

What to expect#

• Latency. A local 7B model on a Mac M-series will produce a translation in 1-3 seconds per key. Bulk operations are sequential per locale, parallel per chunk; expect ~30 seconds per 50 keys on a single locale.
• Quality. Larger models (14B+) match cloud quality on common locale pairs. Smaller models (3B-7B) are adequate for short UI strings; quality drops on complex ICU plurals or rare locale pairs.
• Memory. Plan for the runner to hold the model in VRAM/unified memory while StringLane is open. Quit the runner when you're done if you need the RAM back.

Troubleshooting#

• "Could not reach the model server" error: confirm the runner is up (curl http://localhost:11434/v1/models) and the URL in Settings exactly matches.
• Translation comes back as a code block or refusal: the model is misinterpreting the system prompt. Try a different model; instruction-tuned *-instruct variants behave best.
• Empty translations: the runner returned non-JSON. StringLane's parser logs a TranslationParseError and skips that key. Check the runner's console for the raw response.

Related#

• Set Up AI Translation in 5 Minutes: cloud providers (BYOK).
• How to Translate All Missing Cells at Once: bulk flow that works with any provider.
• How to Use the Issues Panel: Fix-with-AI also runs against your configured provider.