How is this different from a plagiarism or text-compare tool?

Plagiarism and diff tools compare word overlap - the literal characters that match. This calculator compares meaning using AI embeddings, so paraphrased text with no shared words can still score as highly similar.

How is the similarity score calculated?

Each text is converted into an embedding vector with OpenAI's text-embedding-3-small model. The cosine similarity between the two vectors is then rescaled to an intuitive 0-100% score.

Is the semantic similarity calculator free?

Yes. You can compare two texts and get a semantic similarity score for free, with no signup required. Creating an account is optional and only adds saved comparison history.

Semantic Similarity Calculator

Paste two texts and get a 0-100% semantic similarity score. It compares meaning, not word overlap - powered by OpenAI embeddings and cosine similarity.

Text A

Text B

Awaiting input

Enter text in both fields, then measure to see how closely they resonate.

Cosine: ––

DistinctLooseRelatedStrongIdentical

What is semantic similarity?

Semantic similarity measures how close two pieces of text are in meaning, rather than how many words they have in common. Two sentences can share almost no words and still mean the same thing - and this calculator is built to catch exactly that.

Meaning, not word overlap

Plagiarism checkers and text-compare (diff) tools look at literal word overlap. This semantic similarity calculator compares meaning using AI embeddings, so a paraphrase with completely different wording can still score as highly similar. That makes it useful for comparing paraphrases, deduplicating content, matching questions to answers, evaluating model outputs, and checking whether two passages say the same thing.

How the similarity score is calculated

Each text is converted into an embedding vector using OpenAI's text-embedding-3-small model. We then take the cosine similarity between the two vectors and rescale it to an intuitive 0-100% score - higher means closer in meaning.

Frequently asked questions

Is the semantic similarity calculator free?: Yes. You can compare two texts and get a similarity score for free, with no signup required. An account is optional and only adds saved comparison history.
How is this different from a plagiarism or text-compare tool?: Those tools measure word overlap. This one measures meaning, so paraphrased text with no shared words can still score as highly similar.
What is cosine similarity?: Cosine similarity is the cosine of the angle between two vectors. For text embeddings it captures how aligned two meanings are, independent of length.