At first glance, an order book heatmap just looks like a mess of colors. But it really only tracks three things—time, price, and order size. Once you get how these work, you’ll be reading the map in seconds.

Axes

Horizontal axis is time: older data on the left, right edge is now. Vertical axis is price: higher up means higher price. Brightness shows order size at that level and moment—the more volume, the brighter and more yellow it gets.

The white line running across the map is the actual price. Everything else is read relative to it: above the line are sell orders, below are buy orders.

What the Bands Mean

A horizontal band shows an order that’s been sitting there for a while. The longer the band, the longer that volume’s stayed in place. Brighter means bigger size. A long, bright band? That’s your classic wall.

Vertical flashes are quick bursts across price levels—usually bots firing off orders or traders reacting to news, with orders popping in and out almost instantly.

Any empty, dark area just means there aren’t any orders above the set threshold there. That doesn’t mean the book is empty—there’s always small stuff—but no one’s holding serious size at those prices.

Tune the Filter for Your Needs

The slider above the map controls what orders show up. This isn’t just for looks: without a filter, the map is all noise; with it, you see the real structure.

To spot key levels, raise the lower bound so you’re left with just three to five bands. To get a feel for overall market density, drop the filter down. The color scale always stretches to fit your chosen range, so you’ll get clear contrast no matter how you set it.

Picking a Timeframe

A short window (6 or 24 hours) shows you the microstructure right now—where the current range boundaries are. A longer window (3 or 7 days) highlights the big levels that have survived multiple breakout attempts.

Heads up: on a 7-day map, each column covers several hours, so you won’t see split-second events. On a 6-hour map, you’ll miss levels that formed a week ago.

What You Can (and Can’t) Learn From the Map

You can see: where size is concentrated, which side has more volume, if a level has held on past tests, and whether orders get pulled as price approaches.

You can’t see: where price is heading next. The map just shows the current setup, not the outcome. A big support can break if enough sellers show up—it happens all the time.

The smart way to use a heatmap is as context. Say you see that serious support is 3% away, but resistance is close and has held twice already—that shifts your risk assessment for a trade, but it doesn’t make the decision for you.

How to Get Started

Open the BTC order book heatmap on the daily window, double the lower filter threshold, and check out the table below the chart. It shows the same levels in numbers: price, size, distance from current price, and touch history. Match the table to the map a couple of times and you’ll stop seeing just noise.