Skip to main content
Pre-release

This release is a pre-release and may not be stable for production use.

compressed-tensors

The compressed-tensors library extends the safetensors format, providing a versatile and efficient way to store and manage compressed tensor data. This library supports various quantization and sparsity schemes, making it a unified format for handling different model optimizations like GPTQ, AWQ, SmoothQuant, INT8, FP8, SparseGPT, and more.

Why compressed-tensors?

As model compression becomes increasingly important for efficient deployment of LLMs, the landscape of quantization and compression techniques has become increasingly fragmented. Each method often comes with its own storage format and loading procedures, making it challenging to work with multiple techniques or switch between them. compressed-tensors addresses this by providing a single, extensible format that can represent a wide variety of compression schemes.

  • Unified Checkpoint Format: Supports various compression schemes in a single, consistent format.
  • Wide Compatibility: Works with popular quantization methods like GPTQ, SmoothQuant, and FP8. See llm-compressor
  • Flexible Quantization Support:
    • Weight-only quantization (e.g., W4A16, W8A16, WnA16)
    • Activation quantization (e.g., W8A8)
    • KV cache quantization
    • Non-uniform schemes (different layers can be quantized in different ways!)
  • Sparsity Support: Handles both unstructured and semi-structured (e.g., 2:4) sparsity patterns.
  • Open-Source Integration: Designed to work seamlessly with Hugging Face models and PyTorch.

This allows developers and researchers to easily experiment with composing different quantization methods, simplify model deployment pipelines, and reduce the overhead of supporting multiple compression formats in inference engines.

Installation

From PyPI

Stable release:

pip install compressed-tensors

Nightly release:

pip install --pre compressed-tensors

From Source

git clone https://github.com/vllm-project/compressed-tensors
cd compressed-tensors
pip install -e .

Getting started

Saving a Compressed Model with PTQ

We can use compressed-tensors to run basic post training quantization (PTQ) and save the quantized model compressed on disk

model_name = "TinyLlama/TinyLlama-1.1B-intermediate-step-1431k-3T"
model = AutoModelForCausalLM.from_pretrained(model_name, device_map="cuda:0", torch_dtype="auto")

config = QuantizationConfig.parse_file("./examples/bit_packing/int4_config.json")
config.quantization_status = QuantizationStatus.CALIBRATION
apply_quantization_config(model, config)

dataset = load_dataset("ptb_text_only")["train"]
tokenizer = AutoTokenizer.from_pretrained(model_name)

def tokenize_function(examples):
    return tokenizer(examples["sentence"], padding=False, truncation=True, max_length=1024)

tokenized_dataset = dataset.map(tokenize_function, batched=True)
data_loader = DataLoader(tokenized_dataset, batch_size=1, collate_fn=DefaultDataCollator())

with torch.no_grad():
    for idx, sample in tqdm(enumerate(data_loader), desc="Running calibration"):
        sample = {key: value.to(device) for key,value in sample.items()}
        _ = model(**sample)

        if idx >= 512:
            break

model.apply(freeze_module_quantization)
model.apply(compress_quantized_weights)

output_dir = "./ex_llama1.1b_w4a16_packed_quantize"
compressor = ModelCompressor.from_pretrained_model(model)
compressor.compress_model(model)
model.save_pretrained(output_dir)

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

compressed_tensors-0.17.2a20260729.tar.gz (279.5 kB view details)

Uploaded Source

Built Distribution

If you're not sure about the file name format, learn more about wheel file names.

compressed_tensors-0.17.2a20260729-py3-none-any.whl (219.6 kB view details)

Uploaded Python 3

File details

Details for the file compressed_tensors-0.17.2a20260729.tar.gz.

File metadata

File hashes

Hashes for compressed_tensors-0.17.2a20260729.tar.gz
Algorithm Hash digest
SHA256 a9f1455f7ec8a3c48c8d872eb03ea651996238a33f16bf59d47974a14a3a7408
MD5 ba16e467969cad8b9cee3e629d103801
BLAKE2b-256 5d1ce4b216cf3a7673b868f0f9d2304c3e0ea0248acd13120a1d1516a271d2a2

See more details on using hashes here.

Provenance

The following attestation bundles were made for compressed_tensors-0.17.2a20260729.tar.gz:

Publisher: upload.yml on neuralmagic/llm-compressor-testing

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file compressed_tensors-0.17.2a20260729-py3-none-any.whl.

File metadata

File hashes

Hashes for compressed_tensors-0.17.2a20260729-py3-none-any.whl
Algorithm Hash digest
SHA256 f25221b58fa7796838e7ff9fd3583d95e0f16cdc1067d2ac585a10c1d17ca0ab
MD5 0e9e5373450ace02eae54c49d1bd0fbd
BLAKE2b-256 1052b4e9655f7106ed3060e3a9cedac251299bb98ce2e252cc01b1a3f6f3a75c

See more details on using hashes here.

Provenance

The following attestation bundles were made for compressed_tensors-0.17.2a20260729-py3-none-any.whl:

Publisher: upload.yml on neuralmagic/llm-compressor-testing

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

Release history Release notifications | RSS feed

Supported by

AWS Cloud computing and Security Sponsor Datadog Monitoring Depot Continuous Integration Fastly CDN Google Download Analytics Pingdom Monitoring Sentry Error logging StatusPage Status page