📄 ai-sdk/docs/reference/ai-sdk-core/cosine-similarity

File: cosine-similarity.md | Updated: 11/15/2025

Source: https://ai-sdk.dev/docs/reference/ai-sdk-core/cosine-similarity

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cosineSimilarity()

=========================================================================================================

When you want to compare the similarity of embeddings, standard vector similarity metrics like cosine similarity are often used.

cosineSimilarity calculates the cosine similarity between two vectors. A high value (close to 1) indicates that the vectors are very similar, while a low value (close to -1) indicates that they are different.

import { openai } from '@ai-sdk/openai';import { cosineSimilarity, embedMany } from 'ai';
const { embeddings } = await embedMany({  model: openai.textEmbeddingModel('text-embedding-3-small'),  values: ['sunny day at the beach', 'rainy afternoon in the city'],});
console.log(  `cosine similarity: ${cosineSimilarity(embeddings[0], embeddings[1])}`,);

Import


import { cosineSimilarity } from "ai"

API Signature


Parameters

vector1:

number[]

The first vector to compare

vector2:

number[]

The second vector to compare

Returns

A number between -1 and 1 representing the cosine similarity between the two vectors.

On this page

cosineSimilarity()

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