Blame for README.md

---
license: apache-2.0
pipeline_tag: feature-extraction
tags:
- feature-extraction
- sentence-similarity
- mteb
- sentence-transformers
language:
  - multilingual
---


<p align="center">
  <img src="assets/logo.svg" alt="Perplexity Logo" width="400">
</p>

<p align="center">pplx-embed-1: Diffusion-LM for Dense and Contextual Retrieval</p>

`pplx-embed-1` and `pplx-embed-1-context` are state-of-the-art text embedding models optimized for real-world, web-scale retrieval tasks.

- Use **`pplx-embed-1`** for independent text embedding (queries, documents, semantic search)
- Use **`pplx-embed-1-context`** for document chunks in RAG systems where surrounding context matters

![diag.png](assets/diag.png)

## Models

| Model | Dimensions | Context | MRL | Quantization | Instruction | Pooling |
|:-----:|:----------:|:-------:|:---:|:------------:|:-----------:|:-------:|
| `pplx-embed-1-0.6B` | 1024 | 32K | Yes | INT8/BINARY | No | Mean |
| `pplx-embed-1-4B` | 2560 | 32K | Yes | INT8/BINARY | No | Mean |
| `pplx-embed-1-context-0.6B` | 1024 | 32K | Yes | INT8/BINARY | No | Mean |
| `pplx-embed-1-context-4B` | 2560 | 32K | Yes | INT8/BINARY | No | Mean |

<sub>All models are built on diffusion continued pre-trained Qwen3 at Perplexity AI.</sub>

<sub>Many modern embedding models rely on instruction tuning, where users prepend an instruction string to the text being embedded. This can yield a 2%-3% lift on benchmarks, but it also introduces prompt-selection overhead and can make indexing pipelines brittle (small instruction changes can shift embedding space). We deliberately **avoid** this requirement: you can embed the text you want to index directly, without having to choose or maintain an instruction prefix.</sub>

## Usage

<details>
<summary>Via API</summary>

```bash
curl -X POST https://api.perplexity.ai/v1/embeddings \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "texts": [
      "Scientists explore the universe driven by curiosity.",
      "Children learn through curious exploration.",
      "Historical discoveries began with curious questions.",
      "Animals use curiosity to adapt and survive.",
      "Philosophy examines the nature of curiosity.",
    ],
    "model": "pplx-embed-1-0.6B"
  }'
```

</details>


<details>
<summary>Using SentenceTransformers</summary>

```python
from sentence_transformers import SentenceTransformer

model = SentenceTransformer(
    "perplexity-ai/pplx-embed-1-0.6B",
    trust_remote_code=True
)

texts = [
    "Scientists explore the universe driven by curiosity.",
    "Children learn through curious exploration.",
    "Historical discoveries began with curious questions.",
    "Animals use curiosity to adapt and survive.",
    "Philosophy examines the nature of curiosity.",
]

embeddings = model.encode(texts) # Shape: (5, 1024), quantized to int8
embeddings = model.encode(texts, quantization="binary") # Shape: (5, 1024), quantized to binary
```

</details>


## Technical Details

For comprehensive technical details and evaluation results, see our paper on arXiv.

## Contact

- Website: https://perplexity.ai
- API Support: api-support@perplexity.ai