The Evolution of Text Embeddings

Ali Arsanjani
6 min readOct 9, 2023

Text embeddings, also known as word embeddings, are high-dimensional, dense vector representations of text data that enable the measurement of semantic and syntactic similarity between different pieces of text. They are usually created by training machine learning models like Word2Vec, GloVe, or BERT on large amounts of text data. These models are able to capture complex relationships between words and phrases, including semantic meaning, context, and even certain aspects of grammar. These embeddings can be utilized for tasks like semantic search, where pieces of text are ranked based on their similarity in meaning or context, as well as other natural language processing tasks like sentiment analysis, text classification, and machine translation.

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The Evolution and Emergence of Embedding APIs

In the realm of Natural Language Processing (NLP), text embeddings have fundamentally transformed the way we understand and process language data. By translating textual information into numerical data, text embeddings have facilitated the development of sophisticated machine learning algorithms capable of semantic understanding, context recognition, and many more language-based tasks. In this article, we explore the progression of text embeddings and discuss the emergence of embedding APIs.

The Genesis of Text Embeddings

In the early stages of NLP, simple techniques such as one-hot encoding and Bag-of-Words (BoW) were used. However, these methods failed to capture the contextual and semantic intricacies of language. Each word was treated as an isolated unit, without any understanding of its relationship with other words or its usage in different contexts.

Enter Word2Vec

The advent of Word2Vec by Google in 2013 marked a significant leap in NLP. Word2Vec is an algorithm that uses neural networks to learn word associations from a large corpus of text. As a result, it generates dense vector representations, or embeddings, of words that capture a great deal of semantic and syntactic information. The contextual meaning of words can be determined by the closeness of vectors in the high-dimensional space.

GloVe: Global Vectors for Word Representation

Stanford researchers advanced the concept of word embeddings further with the introduction of GloVe in 2014. GloVe improved upon Word2Vec by examining the statistical information more globally over the entire corpus to create word vectors. It allowed for even more nuanced semantic understanding by taking both local context window and global corpus statistics into account.

Transformer-based Embeddings: BERT and Its Variants

The transformer architecture, introduced in 2017, revolutionized NLP by introducing the concept of attention mechanisms. Following this, Google’s BERT (Bidirectional Encoder Representations from Transformers), released in 2018, provided context-dependent word embeddings. BERT considers the full context of a word by looking at the words that come before and after it, unlike Word2Vec and GloVe which are context-free models. Since the release of BERT, several variants and improvements have been developed, like RoBERTa, GPT (Generative Pre-training Transformer), and others.

Emergence of Embedding APIs

Recently, the growth of machine learning applications has driven the development of APIs (Application Programming Interfaces) that offer pre-trained word embeddings. These APIs simplify the task of obtaining word embeddings and allow developers to focus on building applications.

Examples include Google’s TensorFlow Hub, which offers pre-trained models that can generate embeddings. These models include a variety of options, from Word2Vec and GloVe to transformer-based models like BERT. Similarly, Hugging Face’s Transformers library provides a straightforward way to obtain pre-trained transformer embeddings.

Such APIs have significantly democratized access to state-of-the-art NLP technologies. Developers can integrate these APIs into their applications to perform tasks like semantic search, sentiment analysis, text classification, and more, without needing extensive expertise in machine learning or the resources to train such models.

Therefore, we can sum up by saying that Embedding APIs are a type of machine learning API that provides access to pre-trained word embeddings. Word embeddings are vector representations of words that capture their meaning and relationships with other words. They allow implementations of (NLP) tasks, such as semantic search, sentiment analysis, and text classification.

Why are embedding APIs important?

Embedding APIs are important because they make it easy for developers to access state-of-the-art NLP technologies. In the past, developers who wanted to use word embeddings had to train their own models. This was a time-consuming and resource-intensive process. Embedding APIs make it possible for developers to get started with NLP tasks quickly and easily, without needing to have extensive expertise in machine learning.

There are a number of embedding APIs available, including:

  • Google’s PaLM 2, textembedding-gecko@latest
  • Google’s TensorFlow Hub
  • Hugging Face’s Transformers library
  • Stanford’s GloVe library
  • CoVe (Contextual Vectors)
  • FastText
  • ELMo

These APIs offer a variety of pre-trained word embeddings, including Word2Vec, GloVe, and transformer-based models like BERT.

How do embedding APIs work?

When a developer uses an embedding API, they first need to select the pre-trained model that they want to use. The API will then return a vector representation of each word in the input text. The vector representations can then be used to perform NLP tasks.

Benefits of using embedding APIs

  • Ease of use: Embedding APIs make it easy for developers to get started with NLP tasks. They do not require any expertise in machine learning or the resources to train their own models.
  • Accuracy: Embedding APIs offer high accuracy for a variety of NLP tasks. This is because they are trained on large datasets of text and code.
  • Scalability: Embedding APIs are scalable, so they can be used to process large amounts of text.

Embedding APIs are a powerful tool for NLP tasks. They make it easy for developers to access state-of-the-art NLP technologies and perform tasks like semantic search, sentiment analysis, and text classification. As the field of NLP continues to grow, embedding APIs will become even more important.

Use-cases: Semantic aka Vector Search

Vector Search or Semantic Search is one of the first use cases of using embeddings. Here is how to do this with Google AI.

Sample code.


Text embeddings have undergone a significant evolution since the advent of NLP, each advancement bringing us closer to effectively mimicking human understanding of language. With the availability of embedding APIs, these powerful tools have been made accessible to a wide range of developers, further accelerating advancements in NLP applications.

Annotated References

Here are some papers marking the evolution of embeddings.

  • Mikolov, Tomas, et al. “Efficient estimation of word representations in vector space.” (2013). [This paper introduces the Word2Vec model, which is one of the most popular word embedding models.]
  • Pennington, Jeffrey, et al. “Glove: Global vectors for word representation.” Empirical Methods in Natural Language Processing (EMNLP) (2014). [This paper introduces the GloVe model, which is another popular word embedding model.]
  • Devlin, Jacob, Ming-Wei Chang, Kenton Lee, and Kristina Toutanova. “Bert: Pre-training of deep bidirectional transformers for language understanding.” (2018). [This paper introduces the BERT model, which is a transformer-based model that has achieved state-of-the-art results on a variety of NLP tasks.]
  • Radford, Alec, Jeffrey Wu, Rewon Child, David Luan, Dario Amodei, and Ilya Sutskever. “Language models are unsupervised multitask learners.” (2018). [This paper introduces the GPT-2 model, which is a transformer-based model that can generate text, translate languages, write different kinds of creative content, and answer your questions in an informative way.]
  • Brown, Tom B., Benjamin Mann, Nick Ryder, Melanie Subbiah, Jared Kaplan, Prafulla Dhariwal, Arvind Neelakantan, et al. “Language models are few-shot learners.” (2020). [This paper introduces the BART model, which is a transformer-based model that can learn to perform new tasks with very few examples.]



Ali Arsanjani

Director Google, AI/ML & GenAI| EX: WW Tech Leader, Chief Principal AI/ML Solution Architect, AWS | IBM Distinguished Engineer and CTO Analytics & ML