A practical guide to image splitting
Worked examples, tile dimensions, download order and troubleshooting for the controls on this site.
Updated:
| Layout | Controls | Source pixels | Output pixels |
|---|---|---|---|
| Panorama | Vertical · 3 | 3600 × 1200 | 3 × 1200 × 1200 |
| Nine tiles | Grid · 3 × 3 | 3000 × 3000 | 9 × 1000 × 1000 |
| Two rows | Horizontal · 2 | 2400 × 1600 | 2 × 2400 × 800 |
| Uneven columns | Vertical · 3 | 1001 × 600 | 333/334/334 × 600 |
1. Choose the layout before the count
Vertical means columns, cut from left to right. Horizontal means rows, cut from top to bottom. Grid cuts in both directions and accepts 4 tiles (2 × 2) or 9 tiles (3 × 3). It is a square arrangement of pieces; it does not make each piece square automatically.
For a source W pixels wide and H pixels high split into C columns and R rows, a piece is approximately W/C × H/R pixels. To obtain square pieces, prepare a source with W/H = C/R. A 3600 × 1200 panorama divided into three columns yields three 1200 × 1200 images; a 3000 × 2000 photo divided into a 3 × 3 grid yields pieces around 1000 × 667 instead.
2. A three-panel panorama
Choose a 3600 × 1200 test image, select Vertical and set the count to 3. The preview should show two vertical cut lines. Download the ZIP, extract it and view piece_1.png through piece_3.png from left to right. Each should be 1200 × 1200 pixels.
Keep faces, captions and important subjects away from the two cuts. The tool does not add overlap or margins. If a destination crops or resizes images, test one panel there before publishing the full sequence.
3. A nine-tile grid
For nine square tiles, prepare a square source such as 3000 × 3000 pixels in an editor. Select Grid and 3 × 3. The resulting tiles are 1000 × 1000 pixels, ordered left to right across the top row, then the middle row, then the bottom row.
The numbers in the diagram match the filenames. They describe spatial order, not a guaranteed posting order. A service that inserts the newest post first can require reverse posting; profile thumbnails may also use a different crop. Check the current destination preview, account layout and any pinned posts before planning a multi-post image.
4. What happens at uneven edges
Image dimensions are whole numbers. For a width of 1001 pixels divided into three columns, the cut positions are 0, 333, 667 and 1001. The widths are 333, 334 and 334 pixels. The pieces differ by no more than one pixel, cover the full source and have no shared columns.
If every piece must have exactly the same dimensions, crop or pad your original to a multiple of the desired row and column counts first. This tool does not contain a crop or padding control.
5. Understand PNG output
Every piece is exported as PNG, regardless of the source format. The tool uses the source region without resizing and supports transparent pixels, but decoding through a browser canvas can change color handling. Camera metadata, embedded profiles and animation are not retained.
A PNG cut from a compressed JPG can be larger than expected. Splitting is not compression, and it cannot restore missing detail. Keep the original for archival use and compress the pieces separately if your destination has file size limits.
6. Verify before publishing or printing
Extract split_images.zip, count the files and compare their numbered order with the preview. Check their pixel dimensions and inspect the rightmost and bottommost edges. Reassemble them in an editor if alignment matters.
For print, pixel dimensions alone do not establish the paper size. Set physical scale, resolution, margins and bleed in your printing software. For a website, measure total file sizes and use image compression and appropriate loading settings; more files can also mean more requests.
7. Solve a failed operation
If a file is rejected, confirm it is a JPG, PNG, WebP or AVIF and no larger than 10 MB. A valid extension does not guarantee the browser can decode the file; try converting a copy to PNG or JPG.
If processing stops on a phone, reduce the pixel dimensions, close other heavy tabs and try fewer pieces. Decoded images use much more memory than their compressed files. If the ZIP is missing, check your browser download permissions and download folder, then try again. Send a problem report with the browser, dimensions and settings rather than a private image.