Training LLMs to be Better Text Embedders through Bidirectional Reconstruction
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Abstract (arXiv)
Large language models (LLMs) have increasingly been explored as powerful text embedders. Existing LLM-based text embedding approaches often leverage the embedding of the final token, typically a reserved special token such as [EOS]. However, these tokens have not been intentionally trained to capture the semantics of the whole context, limiting their capacity as text embeddings, especially for retrieval and re-ranking tasks. We propose to add a new training stage before contrastive learning to enrich the semantics of the final token embedding. This stage employs bidirectional generative reconstruction tasks, namely EBQ2D (Embedding-Based Query-to-Document) and EBD2Q (Embedding-Based Document-to-Query), which interleave to anchor the [EOS] embedding and reconstruct either side of Query-Document pairs. Experimental results demonstrate that our additional training stage significantly improves LLM performance on the Massive Text Embedding Benchmark (MTEB), achieving new state-of-the-art results across different LLM base models and scales.
Key facts. Cited by 6 papers in the map (data through 14 Oct 2026). Builds on 34 of its 46 references that are in the map. First posted on arXiv 3 Sep 2025.
Builds on
34 of 46 references.
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Citing papers per year: 2025: 1; 2026: 5.
6 papers.
- 2025Learning to Compress: Unlocking the Potential of Large Language Models for Text Representationcited by 3
- 2026LLM-based Embeddings: Attention Values Encode Sentence Semantics Better Than Hidden Statescited by 3
- 2026Learn Before Represent: Bridging Generative and Contrastive Learning for Domain-Specific LLM Embeddingscited by 2
- 2026Embedding-based In-Context Prompt Training for Enhancing LLMs as Text Encoderscited by 0
- 2026ReverseEOL: Improving Training-free Text Embeddings via Text Reversal in Decoder-only LLMscited by 0
- 2026Generative Embedding Benchmark: How Much Information Survives in a Dense Embedding?cited by 0
- 2026Generative Embedding Benchmark: How Much Information Survives in a Dense Embedding?7 Aug 2026
- 2026ReverseEOL: Improving Training-free Text Embeddings via Text Reversal in Decoder-only LLMs4 Jun 2026
- 2026Embedding-based In-Context Prompt Training for Enhancing LLMs as Text Encoders2 May 2026
- 2026LLM-based Embeddings: Attention Values Encode Sentence Semantics Better Than Hidden States2 Feb 2026
- 2026Learn Before Represent: Bridging Generative and Contrastive Learning for Domain-Specific LLM Embeddings16 Jan 2026
- 2025Learning to Compress: Unlocking the Potential of Large Language Models for Text Representation21 Nov 2025