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How to Find Similar Chart Patterns in Seconds

Chart Library Team··5 min read

Why Pattern Similarity Matters

Every trader has had the moment: you're staring at a chart and thinking "I've seen this before." Maybe it's a textbook bull flag, or a slow grind into resistance that looks eerily familiar. The problem is, your memory is unreliable. You remember the wins, forget the losses, and can't objectively measure how similar two patterns really are.

Chart Library solves this by turning pattern recognition into a data problem. Instead of relying on gut feel, you can search across millions of historical chart patterns and find the 10 closest matches — then see exactly what happened next.

Two Ways to Search

Chart Library supports two search modes, each designed for a different workflow.

  • Text search: Type a ticker and date (e.g., "AAPL 2024-06-15") to pull the actual historical data and find similar patterns from the database.
  • Screenshot search: Upload a screenshot of any chart from any platform — TradingView, Thinkorswim, Webull, your broker's app — and the AI extracts the pattern and matches it against history.

How Screenshot Search Works

When you upload a screenshot, Chart Library uses a fine-tuned vision model (DINOv2-ViT-B/14) to convert the visual pattern into a 384-dimensional embedding vector. This vector lives in the same mathematical space as the pre-computed embeddings for every historical chart in the database.

The system then performs an L2 (Euclidean) distance search using pgvector, finding the 10 historical charts whose embedding vectors are closest to your query. The entire search takes about 9 milliseconds.

Reading Your Results

Each search returns an AI-generated summary explaining the pattern and what the historical matches suggest. Below that, you'll see follow-through statistics for 1, 3, 5, and 10-day periods — showing average returns, win rates, and the distribution of outcomes.

The fan chart overlays all 10 match trajectories so you can see the range of possible outcomes at a glance. Individual match cards show the ticker, date, similarity score, and a mini overlay comparing your query pattern to the match.

Tip:Use the Trade Simulator to set stop losses and profit targets on your matches — it simulates what would have happened across all 10 historical outcomes.

Tips for Better Searches

The quality of your results depends on the quality of your query. Here are some tips to get the most out of Chart Library.

  • For screenshots, crop tightly around the price action you care about. Remove indicators, drawing tools, and sidebars.
  • Use the timeframe that matches your trading horizon. A 5-minute chart pattern tells a different story than a daily chart.
  • Check the match scores — anything above 90% is a very strong match. Below 70% means the pattern is fairly unique.
  • Look at the fan chart spread. Tight convergence means the matches agree on direction; wide spread means the pattern is ambiguous.

Get Started

Chart Library offers 3 free searches per day — no account required. Try it with a chart you're currently watching and see what history has to say.

Try Chart Library free — search any chart pattern and see what happened next.

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Upload a chart screenshot or search any ticker — see what history says about your pattern.

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