whichllm

Find the best local LLM that actually runs on your hardware.

Auto-detects your GPU/CPU/RAM and ranks the top models from HuggingFace that fit your system.

日本語版はこちら

Why whichllm?

One command. Real answers. No TUI to learn, no keybindings to memorize.

	whichllm	Others (TUI-based)
Getting results	whichllm — done	Launch TUI → navigate → search → filter
Model data	Live from HuggingFace API	Static built-in database
Benchmarks	Real eval scores with confidence	Fixed quality scores
Scriptable	whichllm --json | jq	Requires special flags
Learning curve	Zero	Vim keybindings required

Features

• Auto-detect hardware — NVIDIA, AMD, Apple Silicon, CPU-only
• Smart ranking — Scores models by VRAM fit, speed, and benchmark quality
• One-command chat — whichllm run downloads and starts a chat session instantly
• Code snippets — whichllm snippet prints ready-to-run Python for any model
• Live data — Fetches models directly from HuggingFace (cached for performance)
• Benchmark-aware — Integrates real eval scores with confidence-based dampening
• Task profiles — Filter by general, coding, vision, or math use cases
• GPU simulation — Test with any GPU: whichllm --gpu "RTX 4090"
• Hardware planning — Reverse lookup: whichllm plan "llama 3 70b"
• JSON output — Pipe-friendly: whichllm --json

Run & Snippet

Try any model with a single command. No manual installs needed — whichllm creates an isolated environment via uv, installs dependencies, downloads the model, and starts an interactive chat.

# Chat with a model (auto-picks the best GGUF variant)
whichllm run "qwen 2.5 1.5b gguf"

# Auto-pick the best model for your hardware and chat
whichllm run

# CPU-only mode
whichllm run "phi 3 mini gguf" --cpu-only

Works with all model formats:

• GGUF — via llama-cpp-python (lightweight, fast)
• AWQ / GPTQ — via transformers + autoawq / auto-gptq
• FP16 / BF16 — via transformers

Get a copy-paste Python snippet instead:

whichllm snippet "qwen 7b"

from llama_cpp import Llama

llm = Llama.from_pretrained(
    repo_id="Qwen/Qwen2.5-7B-Instruct-GGUF",
    filename="qwen2.5-7b-instruct-q4_k_m.gguf",
    n_ctx=4096,
    n_gpu_layers=-1,
    verbose=False,
)

output = llm.create_chat_completion(
    messages=[{"role": "user", "content": "Hello!"}],
)
print(output["choices"][0]["message"]["content"])

Install

pipx (recommended)

pipx install whichllm

Homebrew

brew tap Andyyyy64/whichllm
brew install whichllm

pip

pip install whichllm

Development

git clone https://github.com/Andyyyy64/whichllm.git
cd whichllm
uv sync --dev
uv run whichllm
uv run pytest

Usage

# Auto-detect hardware and show best models
whichllm

# Simulate a GPU (e.g. planning a purchase)
whichllm --gpu "RTX 4090"
whichllm --gpu "RTX 5090"

# CPU-only mode
whichllm --cpu-only

# More results / filters
whichllm --top 20
whichllm --quant Q4_K_M
whichllm --min-speed 30
whichllm --evidence base   # allow id/base-model matches
whichllm --evidence strict # id-exact only (same as --direct)
whichllm --direct

# JSON output
whichllm --json

# Force refresh (ignore cache)
whichllm --refresh

# Show hardware info only
whichllm hardware

# Plan: what GPU do I need for a specific model?
whichllm plan "llama 3 70b"
whichllm plan "Qwen2.5-72B" --quant Q8_0
whichllm plan "mistral 7b" --context-length 32768

# Run: download and chat with a model instantly
whichllm run "qwen 2.5 1.5b gguf"
whichllm run                       # auto-pick best for your hardware

# Snippet: print ready-to-run Python code
whichllm snippet "qwen 7b"
whichllm snippet "llama 3 8b gguf" --quant Q5_K_M

Integrations

Ollama

Find the best model and run it directly:

# Pick the top model and run it with Ollama
whichllm --top 1 --json | jq -r '.models[0].model_id' | xargs ollama run

# Find the best coding model
whichllm --profile coding --top 1 --json | jq -r '.models[0].model_id' | xargs ollama run

Shell alias

Add to your .bashrc / .zshrc:

alias bestllm='whichllm --top 1 --json | jq -r ".models[0].model_id"'
# Usage: ollama run $(bestllm)

Scoring

Each model gets a score from 0 to 100.

Factor	Points	Description
Model size	0-40	Larger models generally produce better output
Benchmark	0-10	Arena ELO / Open LLM Leaderboard scores
Speed	0-20	Higher tok/s = more practical to use
Source trust	-5 to +5	Official repos get a bonus, repackagers get a penalty
Popularity	0-3	Downloads and likes as tiebreaker

Score markers:

• ~ (yellow) — No direct benchmark yet. Score estimated from the model family
• ? (yellow) — No benchmark data available

How it works

Data pipeline

1. Model fetching — Fetches popular models from HuggingFace API:
   • Text-generation (downloads + recently updated)
   • GGUF-filtered (separate query for coverage)
   • Vision models (image-text-to-text) when --profile vision or any
2. Benchmark sources — Chatbot Arena ELO (priority) + Open LLM Leaderboard
3. Benchmark evidence — Four levels of confidence:
   • direct — Exact model ID match
   • variant — Suffix-stripped or -Instruct variant
   • base_model — Base model from cardData
   • line_interp — Size-aware interpolation within model family
4. Cache — ~/.cache/whichllm/:
   • models.json — 6h TTL
   • benchmark.json — 24h TTL

Ranking engine

1. Hardware detection — NVIDIA (nvidia-ml-py), AMD (dbgpu/ROCm), Apple Silicon (Metal), CPU cores, RAM, disk
2. VRAM estimation — Weights + KV cache + activation + framework overhead (~500MB)
3. Compatibility — Full GPU / Partial Offload / CPU-only; compute capability and OS checks
4. Speed — tok/s from GPU memory bandwidth lookup (constants.py)
5. Scoring — Benchmark (with confidence dampening), size, quantization penalty, fit type, speed, popularity, source trust (official vs repackager)
6. Backend filter — Apple Silicon and CPU-only restrict to GGUF for stability; Linux+NVIDIA allows AWQ/GPTQ

Project structure

src/whichllm/
├── cli.py              # Typer CLI: main, plan, run, snippet, hardware
├── constants.py        # GPU bandwidth, quantization bytes, compute capability
├── hardware/
│   ├── detector.py     # Orchestrates GPU/CPU/RAM detection
│   ├── nvidia.py       # NVIDIA GPU via nvidia-ml-py
│   ├── amd.py          # AMD GPU (Linux)
│   ├── apple.py        # Apple Silicon (Metal)
│   ├── cpu.py          # CPU name, cores, AVX support
│   ├── memory.py       # RAM and disk free
│   ├── gpu_simulator.py # --gpu flag: synthetic GPU from name
│   └── types.py        # GPUInfo, HardwareInfo
├── models/
│   ├── fetcher.py      # HuggingFace API, model parsing, evalResults
│   ├── benchmark.py    # Arena ELO, Leaderboard (parquet/rows API)
│   ├── grouper.py      # Family grouping by base_model and name
│   ├── cache.py        # JSON cache with TTL
│   └── types.py        # ModelInfo, GGUFVariant, ModelFamily
├── engine/
│   ├── vram.py         # VRAM = weights + KV cache + activation + overhead
│   ├── compatibility.py# Fit type, disk check, compute/OS warnings
│   ├── performance.py  # tok/s from bandwidth
│   ├── quantization.py # Bytes per weight, quality penalty, non-GGUF inference
│   ├── ranker.py       # Scoring, evidence filter, profile/match
│   └── types.py        # CompatibilityResult
└── output/
    └── display.py      # Rich table, JSON output, hardware/plan displays

Contributing

Contributions are welcome! See CONTRIBUTING.md for guidelines.

Requirements

• Python 3.11+
• NVIDIA GPU detection via nvidia-ml-py (included by default)
• AMD / Apple Silicon detected automatically

License

MIT