In the era of large models, behind the seemingly “intelligent” capabilities of chat, question answering, and analysis, there is actually a key technology: retrieval-augmented generation (RAG).
The performance of a RAG workflow is largely determined by a foundational component –
Embedding.
Among the many open source and commercial embedding models, Jina Embeddings v3 has quickly gained popularity in recent years, becoming one of the strongest open source solutions for the RAG scene. This article will analyze how Jina Embedding + RAG builds a high-quality intelligent Q&A system from an application perspective, and give the actual construction process.
1. What is RAG? Why is it so important?
Large models are not “databases” and do not have “up-to-date knowledge”.
If you think of it as a search engine, it will produce:
- Hallucination
- misquoted
- Outdated information
- Unfounded answers
The purpose of RAG is to give the model a “source of knowledge” that allows it to obtain information from the outside, rather than guessing.
A RAG system typically contains:
- Embedding
- Vector database (store vectors)
- Search module (find the most relevant text)
- Large model generation (answers using search results)
The most crucial of these is Step 1:
👉 The quality of embedding directly determines the search effect.
That’s why Jina Embedding has become a popular choice – it’s specifically optimized for retrieval.
2. Why Choose Jina Embeddings v3?
Jina Embedding’s latest v3 series has several distinct advantages:
(1) Very strong in both Chinese and English
Most open source English models handle Chinese very poorly.
Jina belongs to the model of “natural cross-lingual reinforcement”:
- Both Chinese and English searches performed well
- Chinese semantics are well aligned
- Keywords, sentences, paragraphs can be processed
(2) The ability of long text is stronger than that of similar people
With support for 8192 tokens, long documents can be processed directly without frequent slicing.
(3) Excellent performance in the search task
On MTEB , the world’s most authoritative search list , several tasks are close to OpenAI’s business model.
(4) The model is open source + commercial API is cheap
You can:
- Deploy on your own server (no cost)
- Also use the official API (cheaper than OpenAI, Cohere)
(5) Compatible with all mainstream RAG frameworks
Compatible with:
- Dify
- LlamaIndex
- LangChain
- Qdrant / Pgvector / Milvus
- Elasticsearch
- Weaviate
Especially in the Dify scenario, it is perfectly possible to:
Jina Embedding + Doubao / GPT / DeepSeek, works perfectly
3. RAG workflow: Build an intelligent Q&A system from scratch
Here’s a clear flowchart for you:
原始文档 → 文本分段 → Jina Embedding → 向量数据库
↓
用户提问 → 重写查询 → Embedding
↓
相似度检索
↓
大模型(GPT / Doubao / DeepSeek)
↓
生成回答
The whole process is divided into two parts:
4. Step 1: Build a knowledge base (Embedding + vector storage)
(1) Text slicing (chunking)
Why slicing?
Because the vector model will “dilute the content” when processing long texts, the semantics will be more concentrated after slicing.
Common cutting methods:
- Each paragraph is about 300–500 words
- Keep 15–30 word overlaps
Jina Embedding is strong on long text, but reasonable slicing can still improve accuracy.
(2) Embedding
Feed each piece of text into jina-embeddings-v3:
- Small model: 384 dimensions (fast speed, small memory)
- Large model: 1024 dimensions (higher accuracy)
The output is a dense vector, such as:
[0.12, -0.04, 0.58, 0.33, ...]
This is the “search language” of the RAG system.
(3) Vector storage
You can choose from:
- Qdrant (Open Source, Simple, High Performance)
- Pgvector (PostgreSQL plugin, commonly used by enterprises)
- Milvus (Mass Storage)
- Elasticsearch (your go-to tool)
The tasks of vector storage are:
👉 Quickly find the “most similar” snippet of text.
5. Step 2: Answer user questions (retrieval + large model generation)
When a user asks a question, such as:
“Is Jina Embedding suitable for Chinese?”
The process of RAG is as follows:
① Query Embedding
Convert user questions into vectors with Jina Embedding.
(2) Similarity search
The vector database calculates:
- Cosine similarity
- Dot product
Find the most relevant 3~5 paragraphs of text.
(3) Give the search results to the LLM
LLMs don’t “guess” because you’ve fed it the most relevant material.
The prompt structure is generally as follows:
你是一个基于文档回答问题的 AI。
以下是检索到的知识库内容(非常关键)。
[片段1]
[片段2]
[片段3]
现在回答用户问题:
“Jina Embedding 是否适合中文?”
LLMs (whether GPT, Doubao, or DeepSeek)
Answers are generated based on these fragments.
👉 This is the core advantage of RAG: controllable + precise + explainable.
6. Best practices for building a RAG system with Jina
** Jina v3 small model as a knowledge base (cost-effective)**
For large Chinese business volumes→ 384-dimensional small models are recommended.
** Don’t embed long articles all at once**
While 8192 tokens are supported, slicing is more stable.
** Vector database uses Qdrant or Pgvector **
Lightweight, fast, and many official RAG tutorials.
** The number of searches is controlled between 3~5 items**
Too little affects coverage, too much affects the quality of the build.
** LLM for Doubao / DeepSeek / GPT is acceptable**
Jina is just a low-level retrieval and compatibility is good.
**Dify is the easiest way to deploy**
You are already using Dify → to switch embedding directly.
JINA website: https://jina.ai
Tubing: