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Long Screenshot Stitcher

Long Screenshot Stitcher

Stitch scrolling screenshots into one long image with overlap removal and overlap fine-tuning.

Drag and drop images here or click to browse

Supports PNG / JPEG / WebP / AVIF / HEIC / HEIF

Long Screenshot Stitcher

Quick Start

1
Upload multiple scrolling screenshots
2
Choose Vertical or Horizontal
3
Keep Auto dedupe on; tweak Advanced settings or disable it if detection is unstable
4
If the order is wrong, drag to reorder (or sort by name/time from the Sort menu in the bottom toolbar).
5
Fine-tune seams/crops in Preview first (use ↺ to restore if needed), then open Overlaps to fix low-confidence boundaries, and download

Preview Fine-tuning

  • In Preview, click the button on a seam to unlock (shows ✓). The view will auto-focus on that seam when needed; left-drag either image around the seam to fine-tune alignment (the seam line stays fixed). Right-drag pans the view; mouse wheel zooms.
  • When ↺ appears on a seam, click it to restore that seam’s adjustments.
  • For Top/Bottom (or Left/Right), unlock the edge button and drag near the edge in a large area to adjust cropping; the buttons follow the edge.
  • When ↺ appears on the edge, click it to restore cropping to 0.

Common Scenarios

Stitch scrolling web page screenshots (articles/docs/etc.)

Merge chat log screenshots (WhatsApp/Telegram/etc.)

Combine comics or long images in parts (needs stable overlap)

Join horizontal scrolling/panorama segments (Horizontal mode)

Dedupe & Overlap Settings

  • Direction: Vertical/Horizontal stitching.
  • Auto dedupe: detects overlap between adjacent screenshots and removes duplicates.
  • Overlaps panel: manually enter overlap pixels per boundary (used for dedupe cropping); clear to return to auto. Works best together with Preview fine-tuning.
  • Max/Min overlap: narrows the search range to reduce false positives.
  • Tolerance / Scan step: higher tolerance is more forgiving; smaller step is more accurate but slower.
  • Diff / Confidence: lower diff and higher confidence means more reliable; review low-confidence boundaries.
  • Smart sort (experimental): tries to infer order automatically; may be unreliable with many/similar images.

Usage Advice

Keep ~10–30% overlap between screenshots and avoid large dynamic regions (video/animations/infinite scroll).
If detection is unstable, fix the order first (drag, sort by time, reverse). Correct order usually matters more than tweaking.
Tune one parameter at a time: start with max/min overlap, then adjust tolerance/step for fine-tuning.
For low-confidence boundaries, manually set overlaps or temporarily disable auto dedupe before exporting.
If the output is very large, set a max export size to reduce memory usage and export failures.

Limitations & Compatibility

Requires stable overlap between adjacent screenshots; with no overlap or huge content differences, auto dedupe won't work.
Dynamic content can confuse detection and cause duplicates/missing parts.
Many/high-res screenshots can be memory-heavy and slow; try batching or resizing first.
Use the latest Chrome/Edge/Firefox or Safari 16+ (HEIC/HEIF support varies by browser).

Privacy & Security

All processing happens in your browser; data never leaves your device

FAQ

6

Continue with these related tools for the next step.