Back to Gap Map Model components / Embeddings & retrieval models

all-MiniLM

UKP Lab (TU Darmstadt)
open source / Overall score: 2.9

all-MiniLM maps a sentence or paragraph to a 384-dimensional dense vector for semantic search, clustering and retrieval-augmented generation. It runs a six-layer distilled MiniLM encoder contrastively fine-tuned on more than a billion sentence pairs, and truncates input beyond 256 word pieces. A paraphrase-multilingual sibling carries the same architecture across fifty-odd languages. The Sentence-Transformers project ships both.

Scored as the model family, not the sentence-transformers library, which is a separate product surface with its own PyPI channel. The two declared checkpoints are the ones the project fronts; ONNX, OpenVINO and quantized re-uploads published by third parties are not counted.

Openness

5 high confidence
5.0
weights
open(Apache-2.0 ungated safetensors, PyTorch, ONNX and OpenVINO files)
data
open(all-MiniLM-L6-v2's 1.17B-pair corpus is a concatenation of named public datasets with per-dataset sampling weights in data_config.json)
code
open(train_script.py ships in the all-MiniLM-L6-v2 repository
license
Apache-2.0(OSI)

The headline checkpoint releases the whole contrastive run under Apache-2.0: the corpus is a list of named public datasets, the sampling weights ship as data_config.json, and the training script sits beside the weights. The MLM pretraining of the underlying MiniLM encoder is Microsoft's and is not part of this release.

Adoption

5 high confidence
5.0

Adoption is measured as Hugging Face downloads for all-MiniLM-L6-v2 and its paraphrase-multilingual sibling, the two checkpoints the project fronts, out of fourteen MiniLM checkpoints the sentence-transformers account publishes in total. Third-party re-uploads, format conversions and the separate sentence-transformers PyPI package are excluded.

Capability

2 high confidence
2.0

All-MiniLM is narrow and dated: the headline checkpoint is English-only, truncates at 256 word pieces, and is an early distillation model. It sits a step below E5, which reaches the same short context but publishes multilingual retrieval numbers.

Verified 2026-09-11