Back to Peft

UniLoRA

docs/source/package_reference/unilora.md

0.20.03.1 KB
Original Source
<!--Copyright 2025 The HuggingFace Team. All rights reserved. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. ⚠️ Note that this file is in Markdown but contain specific syntax for our doc-builder (similar to MDX) that may not be rendered properly in your Markdown viewer. -->

UniLoRA

Uni-LoRA is a PEFT method that shares a compact trainable vector bank across low-rank adapter weights. Instead of learning every LoRA matrix element independently, UniLoRA deterministically projects entries into shared theta_d values and learns the shared parameters used by the adapter update.

Quick Start

python
from peft import UniLoraConfig, get_peft_model
from transformers import AutoModelForCausalLM

model = AutoModelForCausalLM.from_pretrained("meta-llama/Llama-3.2-3B")

config = UniLoraConfig(
    r=32,
    theta_d_length=256,
    proj_seed=42,
    target_modules=["q_proj", "v_proj"],
    unilora_dropout=0.0,
    init_weights=True,
    task_type="CAUSAL_LM",
)

peft_model = get_peft_model(model, config)
peft_model.print_trainable_parameters()

Important Parameters

r controls the low-rank adapter dimension. Larger values increase adapter capacity and memory use.

theta_d_length controls the length of the shared UniLoRA vector bank. This is the main trainable storage shared by the projected adapter entries.

proj_seed controls deterministic index generation for the fixed projections into theta_d. Reusing the same seed and configuration makes the generated adapter indices reproducible.

target_modules selects which modules receive UniLoRA adapters. Use module suffixes such as ["q_proj", "v_proj"], a regex string, or "all-linear" when supported by the model architecture.

unilora_dropout applies dropout inside UniLoRA adapter layers during training.

init_weights controls UniLoRA parameter initialization. Set it to False to keep a random theta_d initialization when you need to manage initialization manually.

save_indices controls whether UniLoRA checkpoints save the generated index and scale tensors together with the shared theta_d parameters. Keeping this disabled gives smaller checkpoints and regenerates indices from proj_seed; enabling it makes saved adapters independent from future index-generation changes.

Benchmark overview

<iframe src="https://peft-internal-testing-peft-method-comparison-embed.hf.space/?highlight[type]=UNILORA" frameborder="0" width="850" height="1000" ></iframe>

API

UniLoraConfig

[[autodoc]] tuners.unilora.config.UniLoraConfig

UniLoraModel

[[autodoc]] tuners.unilora.model.UniLoraModel