📊 RGB Histogram

An RGB histogram is a graphical representation showing how pixels are distributed across 256 intensity levels (0–255) for each color channel — Red, Green, and Blue — in a digital image. The horizontal axis represents the intensity value, while the vertical axis shows how many pixels have that value. It helps photographers and designers evaluate exposure, contrast, and color balance at a glance.

Peaks clustered on the left indicate dark/underexposed areas (shadows). Peaks on the right suggest bright/overexposed regions (highlights). A broad spread across the middle typically means good contrast. If one channel's peak is shifted relative to others, there's a color cast — for example, a red channel shifted right indicates a warm/reddish tone dominance.

An RGB histogram shows three separate distributions (per channel), while a luminance histogram combines them into one using a weighted formula (Y = 0.299R + 0.587G + 0.114B) that mimics human brightness perception. RGB per‑channel view reveals color-specific issues like clipping in a single channel that a luminance histogram might hide.

There's no single "correct" histogram — it depends on the image content. A high-key portrait will naturally skew right; a night scene will skew left. The goal is to avoid clipping (spikes at 0 or 255) unless intentional. Generally, a well-exposed image has data spread across the full range without hard cutoffs at either end.

Yes. By comparing the Red, Green, and Blue histograms side-by-side, you can identify color imbalances. If the blue channel's distribution is shifted left compared to red and green, the image likely has a yellow/orange cast. Aligning the channels' distributions (via white balance or levels adjustment) is a common color correction technique.

No. This tool runs entirely in your browser using JavaScript and HTML5 Canvas. Your image is processed locally — nothing is ever uploaded, transmitted, or stored on any server. You can verify this by disconnecting your internet after the page loads; the tool will continue working perfectly.

All common web formats are supported: PNG, JPEG, WebP, GIF, BMP, and SVG (rasterized). For best results, use 8-bit per channel images. 16-bit or HDR images will be tone-mapped by the browser. HEIC/HEIF support depends on your browser and OS.