← AI Terminology

CLIP Score

CLIP Score measures alignment between an image and a text caption using CLIP embeddings’ similarity — higher means better text–image match.

Common for text-to-image evaluation and filtering.
Why It Matters in AI
FID ignores prompts; CLIP Score checks whether the image matches the text. Used to evaluate T2I models, rank samples, and filter noisy image–text web data for training.
Key Points
Aspect Description
Use T2I eval, rerank samples, data filtering
Limits CLIP’s own biases and failure modes
Method cosine(CLIP_image(x), CLIP_text(t))
Related CLIP, FID, human preference (PickScore, etc.)
Variants RefCLIPScore with references
Training data Keep high CLIP-score pairs from the web
Simple Analogy
A bilingual critic scoring how well a poster matches its slogan — not whether the poster looks photographic alone.
Common Usage Examples
  • Rank 8 diffusion samples by CLIP Score
  • Filter LAION-style datasets
  • Report CLIP Score beside FID
  • Watch gaming via adversarial images
Summary
In short: CLIP Score rates text–image alignment via CLIP similarity — the go-to automatic metric for prompt fidelity in image generation.