What does the Heatmap Overlay show?

It offsets the pattern by 50% (placing the edges in the center) and highlights non-matching pixels in glowing red.

Seamless Checker

Analyze pattern tiles to detect seams. Displays a seamless score, edge similarity percentage, and offsets the image with a red mismatch heatmap.

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Upload Image

Click or drag & drop

PNG, JPG, WEBP up to 10MB

Compression Quality: 80%

Width (px)

Height (px)

Lock Aspect Ratio

Scale Percentage: 50%

Preset Crop Proportions

Convert to Format

Angle Direction

Mirror Canvas

Custom Brand Text

Color Plate

Size: 48px

Upload PNG Watermark Image

Grid / Align Layout

Horizontal Offset: 0

Vertical Offset: 0

Rotation Angle: 0

Opacity Layer: 30%

Brush/Erase Tool Action

Click and drag on the preview image right to brush red mask markings over watermark stamps, then click Process Design.

Replace Background Color

Transparent White Black Green Screen Blue Screen Custom

Grid Repeats

Seam Match Tolerance: 25

Display Boundary Mismatch Heatmap

Paste HTML/SVG Code Content

Enter Website URL

Save Format

Colors limit: 8

Detail Factor: 50%

Output print DPI Target

CMYK Channel Plates

Format Export

Super-Resolution Scale

Seamless Border Protection

Erase/Blur Face Radius: 15px

Brightness Adjustment: 0

Contrast Adjustment: 0

Saturation Level: 0

Exposure Level: 0

Sharpness weight: 0%

Gaussian Blur: 0px

✨ Your checker analysis result will appear here

Selected Files (0)

Reset / Upload New

Processing Artwork

Initializing canvas arrays...

Why Choose Our AI Tool?

Automated Boundary Scan

Analyzes outer margins to detect repeating mismatches.

Mismatch Heatmap Overlay

Highlights non-matching pixel borders in glowing red.

Numerical Integrity Score

Calculates a precision seamless score from 0 to 100.

How It Works

Upload Pattern

Upload your repeating design tile.

Run Edge Scan

The checker calculates boundary similarities.

Check Heatmap

Inspect highlighted red mismatch spots in offset preview.

Perfect For

🎨 Designers 👕 Print on Demand 🏷️ Logo Creation ✏️ Illustrators 🛍️ Merch Makers

Seamless Pattern Checker & Heatmap

Inspect pattern tiles for repeating errors. The tool scans edge boundaries (top-bottom, left-right) to calculate similarity scores and offsets the tile, highlighting non-matching boundary pixels in red.

Border alignment scan Red mismatch heatmap 0-100 repeat score Local V8 pixel analysis

Identify repeating lines and offset coordinates before exporting print-ready files. All pixel arrays are analyzed locally in browser JS memory, ensuring high-res repeat safety.