deepset-ai--haystack/docs-website/versioned_docs/version-2.21/pipeline-components/rankers/jinaranker.mdx

---
title: "JinaRanker"
id: jinaranker
slug: "/jinaranker"
description: "Use this component to rank documents based on their similarity to the query using Jina AI models."
---

# JinaRanker

Use this component to rank documents based on their similarity to the query using Jina AI models.

<div className="key-value-table">

|  |  |
| --- | --- |
| **Most common position in a pipeline** | In a query pipeline, after a component that returns a list of documents (such as a [Retriever](../retrievers.mdx) ) |
| **Mandatory init variables** | `api_key`: The Jina API key. Can be set with `JINA_API_KEY` env var. |
| **Mandatory run variables** | `query`: A query string  <br /> <br />`documents`: A list of documents |
| **Output variables** | `documents`: A list of documents |
| **API reference** | [Jina](/reference/integrations-jina) |
| **GitHub link** | https://github.com/deepset-ai/haystack-core-integrations/tree/main/integrations/jina |

</div>

## Overview

`JinaRanker` ranks the given documents based on how similar they are to the given query. It uses Jina AI ranking models – check out the full list at Jina AI’s [website](https://jina.ai/reranker/). The default model for this Ranker is `jina-reranker-v1-base-en`.

Additionally, you can use the optional `top_k` and `score_threshold` parameters with `JinaRanker` :

- The Ranker's `top_k` is the number of documents it returns (if it's the last component in the pipeline) or forwards to the next component.
- If you set the `score_threshold` for the Ranker, it will only return documents with a similarity score (computed by the Jina AI model) above this threshold.

### Installation

To start using this integration with Haystack, install the package with:

```shell
pip install jina-haystack
```

### Authorization

The component uses a `JINA_API_KEY` environment variable by default. Otherwise, you can pass a Jina API key at initialization with `api_key` like this:

```python
ranker = JinaRanker(api_key=Secret.from_token("<your-api-key>"))
```

To get your API key, head to Jina AI’s [website](https://jina.ai/reranker/).

## Usage

### On its own

You can use `JinaRanker` outside of a pipeline to order documents based on your query.

To run the Ranker, pass a query, provide the documents, and set the number of documents to return in the `top_k` parameter.

```python
from haystack import Document
from haystack_integrations.components.rankers.jina import JinaRanker

docs = [Document(content="Paris"), Document(content="Berlin")]

ranker = JinaRanker()

ranker.run(query="City in France", documents=docs, top_k=1)
```

### In a pipeline

This is an example of a pipeline that retrieves documents from an `InMemoryDocumentStore` based on keyword search (using `InMemoryBM25Retriever`). It then uses the `JinaRanker` to rank the retrieved documents according to their similarity to the query.

```python
from haystack import Document, Pipeline
from haystack.document_stores.in_memory import InMemoryDocumentStore
from haystack.components.retrievers.in_memory import InMemoryBM25Retriever
from haystack_integrations.components.rankers.jina import JinaRanker

docs = [
    Document(content="Paris is in France"),
    Document(content="Berlin is in Germany"),
    Document(content="Lyon is in France"),
]
document_store = InMemoryDocumentStore()
document_store.write_documents(docs)

retriever = InMemoryBM25Retriever(document_store=document_store)
ranker = JinaRanker()

ranker_pipeline = Pipeline()
ranker_pipeline.add_component(instance=retriever, name="retriever")
ranker_pipeline.add_component(instance=ranker, name="ranker")

ranker_pipeline.connect("retriever.documents", "ranker.documents")

query = "Cities in France"
ranker_pipeline.run(
    data={
        "retriever": {"query": query, "top_k": 3},
        "ranker": {"query": query, "top_k": 2},
    },
)
```