
E5-base-v2
109M-parameter English text embedding model with 768-dim vectors.
About
E5-base-v2 is Microsoft's workhorse English text embedding model, part of the E5 family from the unilm project. With 12 layers, 109 million parameters and 768-dimensional embeddings, it delivers strong retrieval performance on the BEIR benchmark while remaining small enough to run anywhere — a go-to default for semantic search, clustering and classification pipelines.\n\nThe v2 generation improved on the original E5 models with better contrastive pretraining, and the model is a staple baseline in embedding benchmarks and RAG evaluations. It is distributed under the MIT license, making it free for commercial use.\n\nUsage follows a simple convention: prefix inputs with 'query: ' or 'passage: ' for retrieval tasks, or 'query: ' alone for other tasks, then average-pool and normalize the outputs.
Specs
Context window
Pricing
Free quota
API access
Weights
Released
Benchmarks
Provider-reported unless a source says otherwise. Benchmarks are marketing-adjacent by nature — treat them as directional.
Use cases
Trust score — 8/10
Scored 8/10 (verified tier, metrics-v1). Evidence: Verified via vendor site/docs/GitHub and reputable coverage, wave 121; Trending score 85/100 from researcher assessment.