Shadow Consistency Analyzer
Estimate light source direction from shadow edges across the image. Consistent arrows suggest a single light source. Diverging directions may indicate compositing from different scenes.
600+ images checked for shadow consistency
Drag & drop a file here, Ctrl+V to paste, oror
Light Source Estimation
Shadows reveal where the light came from. This tool estimates the light direction per region by analyzing the gradient orientation at shadow edges — the transition between dark and bright areas.
Composite Detection
When someone composites objects from different photos, the shadows often point in different directions because the original scenes had different lighting. This inconsistency is hard to fix convincingly.
Direction Arrow Overlay
Color-coded arrows show the estimated light direction for each block. Parallel arrows mean consistent lighting. Diverging arrows flag suspicious regions. Toggle arrows and heatmap independently.
How shadow analysis detects fakes
Every shadow in a photo points away from its light source. In a genuine scene with a single dominant light (the sun, a studio light), all shadows should point roughly the same direction. When someone composites objects from different photos, the pasted elements carry shadows from their original light source — creating directional inconsistencies that are difficult to fix convincingly. This tool estimates the light direction per grid block by analyzing shadow edge gradients. For compression-level forgery detection, combine with the ELA Scanner or JPEG Ghost Scanner.
Reading the arrow overlay
Each arrow represents the estimated light source direction for one grid block. Parallel arrows (all pointing the same way) indicate a consistent single light source. Arrows that diverge significantly from the group are color-coded: green means aligned, yellow means moderate deviation, and red means a strongly different direction. Gray blocks lack enough shadow edges for reliable analysis — common in bright or flat areas. For lighting inconsistency from a different angle, check the Luminance Gradient tool which maps brightness surface irregularities.
Limitations and false positives
Shadow analysis has inherent limitations. Multiple light sources in a single scene (e.g. indoor mixed lighting, stadium lights) legitimately produce different shadow directions. Curved surfaces create shadows that change direction gradually. Reflective surfaces can redirect light, producing unexpected shadow angles. Flat or overexposed regions may lack shadow edges entirely. Use shadow analysis as one signal among many — cross-reference with Noise Analysis, Chromatic Aberration, and the Authenticity Checker for a comprehensive assessment.
Combining with other forensic tools
Shadow consistency is strongest when combined with other manipulation detectors. Check Clone Detection for copy-paste regions. Use CFA Pattern Analysis to verify camera sensor fingerprints. Run the Forgery Heatmap for a combined probability overlay. Together these tools cover compression artifacts, sensor-level patterns, pixel-level cloning, and now physical lighting consistency. Explore all forensic and utility tools at Scanly's full toolkit.
Shadow analysis runs entirely in your browser using a Web Worker — your images are never uploaded. The arrow overlay and heatmap can be downloaded as a PNG for forensic reports. Start with the EXIF Checker to examine metadata before running pixel-level analysis. Learn more in our articles on detecting edited photos and image forensics guide.