Gemini Embedding 2 vs CLIP: Which Multimodal Embedding Model Should I Choose?
The Problem
I was building an image search feature for my application. Users wanted to search for products using natural language queries like “red sneakers for running” or find visually similar images by uploading a photo.
I knew I needed multimodal embeddings - a way to represent both images and text in the same vector space so they could be compared. But I got stuck at the first decision point:
Should I use CLIP or try the new Gemini Embedding 2?
CLIP has been around since 2021 and I’ve used it before. But I kept seeing announcements about Gemini Embedding 2 being “natively multimodal.” Was the newer model worth switching to?
What I Thought I Knew
I initially assumed newer meant better. I thought:
- Gemini Embedding 2 must be superior because it’s from Google and released in 2024
- CLIP is old (2021) and probably outdated
- A “unified architecture” sounds better than “separate encoders”
But when I started researching, I found out the reality is more nuanced.
The Reddit Thread That Changed My Perspective
I found a discussion on r/MachineLearning where someone asked about Gemini Embedding 2. The top comment threw me off:
“We already had multimodal embeddings for… quite a while though.”
Wait, what? If multimodal embeddings aren’t new, what makes Gemini Embedding 2 different?
Another user clarified:
“Yes, there’s a bit of nuance but the general idea of multimodal embeddings is that it covers multiple modalities right? We’ve had that for quite a while (look up CCA, that’s >20 years old already!). Then there’s Siamese networks, CLIP and the entirety of deep learning that comes into the frame.”
The OP then clarified what I had missed:
“It’s the first Google natively multimodal embedding model.”
So Gemini Embedding 2 isn’t the first multimodal embedding - it’s Google’s first native multimodal embedding model. That’s a crucial distinction I needed to understand.
The Architecture Difference
Once I understood the distinction, I dug into the architectures.
CLIP: Separate Encoders, Joint Space
CLIP uses two separate neural networks - one for images (ViT) and one for text (Transformer). They’re trained together with contrastive loss to align their outputs in a shared embedding space.
Image Encoder (ViT) ──────┐ ├──> Joint Embedding SpaceText Encoder (Transformer)┘This approach works well. I’ve used CLIP for image-text similarity tasks and it reliably finds semantic matches.
Gemini Embedding 2: Unified Encoder
Gemini Embedding 2 uses a single unified model that processes all modalities - text, images, and audio - through the same architecture.
Unified Multimodal Encoder├── Image Input ────┐├── Text Input ─────┼──> Shared Embedding Space├── Audio Input ────┘The key insight I got from the Reddit discussion:
“What Gemini does is encoding it into a shared space. This is a truly different architecture, but when looking at applications not really that different from the classical network that has graphs for each modality that embed first and later get joined in a single space.”
So in practice, for many applications, the difference may be subtle. But the unified approach could potentially capture deeper cross-modal relationships.
My Comparison Table
After researching, I built this comparison for my own decision-making:
| Aspect | CLIP | Gemini Embedding 2 |
|---|---|---|
| Architecture | Separate encoders | Unified encoder |
| Training | Contrastive learning on image-text pairs | Multimodal native training |
| Modalities | Image, Text | Image, Text, Audio |
| Embedding Space | Joint space via contrastive alignment | Natively shared space |
| Self-hostable | Yes (open weights) | No (API only) |
| Cost | Free for self-hosted | Pay per API call |
| Offline use | Yes | No |
The last three rows became the deciding factors for my project.
Code Examples: What I Tried
I tested both approaches to see how they differ in practice.
Using CLIP for Image-Text Search
First, I tried the familiar CLIP approach:
import torchfrom transformers import CLIPProcessor, CLIPModelfrom PIL import Image
# Load CLIP model (runs locally, no API key needed)model = CLIPModel.from_pretrained("openai/clip-vit-base-patch32")processor = CLIPProcessor.from_pretrained("openai/clip-vit-base-patch32")
# Compare image with text candidatesimage = Image.open("product.jpg")texts = ["a photo of a dog", "a photo of a cat", "a product photo"]
inputs = processor(text=texts, images=image, return_tensors="pt", padding=True)outputs = model(**inputs)
# Get similarity scoreslogits_per_image = outputs.logits_per_imageprobs = logits_per_image.softmax(dim=1)
print(f"Most similar text: {texts[probs.argmax()]}")print(f"Probabilities: {probs}")CLIP worked immediately. I liked that I could run it entirely offline after downloading the model weights.
Using Gemini Embedding 2
Then I tried Gemini Embedding 2:
import google.generativeai as genaifrom PIL import Image
# Configure API keygenai.configure(api_key="YOUR_API_KEY")
# Embed texttext_embedding = genai.embed_content( model="models/text-embedding-004", content="A sunset over mountains", task_type="retrieval_document")
# Embed imageimage = Image.open("landscape.jpg")image_embedding = genai.embed_content( model="models/gemini-embedding-2", content=image, task_type="retrieval_document")
# Calculate similarityimport numpy as npfrom sklearn.metrics.pairwise import cosine_similarity
similarity = cosine_similarity( [text_embedding["embedding"]], [image_embedding["embedding"]])[0][0]
print(f"Text-Image similarity: {similarity}")The API was straightforward, but I noticed two things:
- I needed an internet connection and API key
- Each call cost money (though the pricing is reasonable)
Building a Multimodal Search System
I built a simple abstraction to compare both approaches:
import numpy as npfrom sklearn.metrics.pairwise import cosine_similarityfrom abc import ABC, abstractmethod
class MultimodalSearch(ABC): def __init__(self): self.embeddings = [] self.metadata = []
def index_image(self, image_path, metadata=None): """Index an image with optional metadata""" embedding = self._get_image_embedding(image_path) self.embeddings.append(embedding) self.metadata.append(metadata or {"path": image_path})
def search_by_text(self, query_text, top_k=5): """Search indexed images using text query""" query_embedding = self._get_text_embedding(query_text) similarities = cosine_similarity([query_embedding], self.embeddings)[0] top_indices = np.argsort(similarities)[-top_k:][::-1] return [(self.metadata[i], similarities[i]) for i in top_indices]
@abstractmethod def _get_image_embedding(self, image_path): pass
@abstractmethod def _get_text_embedding(self, text): passThis let me swap between CLIP and Gemini Embedding 2 without changing my application code.
What I Got Wrong
I made several mistakes in my initial evaluation:
Mistake 1: Assuming “native multimodal” means better quality
The unified architecture sounds impressive, but I couldn’t find benchmarks showing it’s significantly better than CLIP for my use case (image-text search). The architecture difference matters more for some applications than others.
Mistake 2: Ignoring deployment constraints
I initially focused only on embedding quality. But for my application:
- Running on edge devices? CLIP wins (can run offline)
- Processing sensitive data? CLIP wins (no API calls)
- Need audio support? Gemini Embedding 2 wins
Mistake 3: Not benchmarking on my actual data
I should have tested both on my specific images and queries. Generic benchmarks don’t capture how well a model works for your particular domain.
Mistake 4: Overlooking rate limits
Gemini Embedding 2 has API rate limits. For batch processing millions of images, CLIP’s unlimited self-hosted approach made more sense.
When to Use Each
Based on my research and testing, here’s when I’d choose each:
Use CLIP When:
- You need offline processing - CLIP runs entirely locally after downloading weights
- You have strict data privacy requirements - No data leaves your servers
- You’re processing at scale - No per-call costs, no rate limits
- You need predictable latency - No network calls means consistent response times
- You’re already in the Hugging Face ecosystem - Easy integration with existing pipelines
Use Gemini Embedding 2 When:
- You need audio embeddings - CLIP only handles image and text
- You’re building within Google Cloud - Native integration with other Google AI services
- You want simpler setup - No model management, just API calls
- Your data is already in Google Cloud - Reduced data transfer costs
- You need Google’s multimodal understanding - Potentially better for complex cross-modal queries
The Decision Framework I Used
I created this simple decision tree for my project:
Need audio embeddings?│├── YES ──> Gemini Embedding 2│└── NO │ Offline/edge deployment needed? │ ├── YES ──> CLIP │ └── NO │ Sensitive data (can't send to API)? │ ├── YES ──> CLIP │ └── NO │ Already using Google Cloud? │ ├── YES ──> Gemini Embedding 2 │ └── NO ──> CLIP (simpler, free, proven)What I Chose
For my image search application, I went with CLIP because:
- I need to process images offline on edge devices
- I want predictable latency without network calls
- I have no audio requirements
- I’m cost-sensitive and processing millions of images
But I’m keeping Gemini Embedding 2 in mind for future projects that might need audio or where I’m already invested in Google’s ecosystem.
Summary
In this post, I compared Gemini Embedding 2 and CLIP for multimodal embeddings. The key insight is that “native multimodal” doesn’t automatically mean better - it depends on your use case.
CLIP remains a solid choice for image-text tasks with proven reliability, offline capability, and zero marginal cost at scale. Gemini Embedding 2 offers audio support and simpler API-based integration, but requires network access and per-call costs.
The best approach is to benchmark both on your actual data before committing. Architecture differences matter less than how the model performs on your specific task.
Final Words + More Resources
My intention with this article was to help others share my knowledge and experience. If you want to contact me, you can contact by email: Email me
Here are also the most important links from this article along with some further resources that will help you in this scope:
- 👨💻 Google AI Gemini Embedding Documentation
- 👨💻 OpenAI CLIP Paper
- 👨💻 Reddit Discussion on Multimodal Embeddings
- 👨💻 Hugging Face CLIP Models
Oh, and if you found these resources useful, don’t forget to support me by starring the repo on GitHub!
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