Open an image
JPG, PNG, or WebP
The source stays on this device. Only Use in Rasterbator writes the generated crop to local IndexedDB so the poster maker can reopen it.
Crop an image locally to precise pixels or paper ratios, then check its 300 DPI print size before poster layout.
Browser Canvas decodes, crops, and exports locally. Drag the frame, pull a corner, or type exact X/Y/W/H pixels without sending the source to a server.
JPG, PNG, or WebP
The source stays on this device. Only Use in Rasterbator writes the generated crop to local IndexedDB so the poster maker can reopen it.
Drag, resize, lock a ratio, or type exact pixels
A4 portrait uses 210 × 297 mm and a 1:1.4142 ratio. Letter uses 8.5 × 11 in. Poster portrait uses 2:3, including common 24 × 36 in artwork.
Pixels, print size, format, and poster handoff
File size is an estimate based on pixel count and format; the exact compressed size depends on image detail. The generated Blob is the file used for download and Rasterbator handoff.
The crop box defines the exact pixels that survive. That makes framing, paper ratio, and usable print size visible before the file enters a tiled poster workflow.
A4 is 210 × 297 mm with the familiar 1:1.4142 ratio. Letter is 8.5 × 11 in, while a 2:3 poster ratio fits sizes such as 24 × 36 in.
Locking one of those ratios keeps the crop frame in that shape while you drag a corner. Free mode removes the ratio constraint when the composition matters more than a standard paper shape.
X and Y set the crop origin in source pixels. W and H set the surviving pixel dimensions, so you can repeat a crop or align it to artwork measurements without estimating by eye.
When a ratio is locked, changing W or H adjusts the other dimension and keeps the rectangle inside the source image.
At 300 DPI, every printed inch needs 300 pixels. A 2550 × 3300 px crop therefore maps to 8.5 × 11 in before any printer-specific bleed is added.
The live readout shows inches and centimeters for the current crop so you can decide whether to continue, resize, upscale, or choose a different frame.
Paper shape, viewing distance, subject scale, and edge content should guide how much of an image survives.
Paper size should come before framing. A 16 × 20 in print uses a 4:5 crop, every ISO A-series sheet keeps the 1:1.4142 relationship, and a 2:3 crop matches formats such as 24 × 36 in.
Measure the intended wall area, frame opening, or paper stock before trimming pixels. A free image cropper for printing is most useful when the final physical shape is known before composition decisions become irreversible.
Viewing distance changes how aggressively you can crop. A large poster seen from across a room can tolerate a tighter frame because the subject still reads clearly at distance.
For a small proof, desk print, or hand-held sample, leave more breathing room around the subject. Close viewing makes clipped edges and crowded borders feel more obvious than they do on a monitor.
Subject scale matters as much as crop ratio. A person, product, or focal object that feels large enough on screen can still look unexpectedly small once the image is printed at the chosen paper size.
Use the live 300 DPI dimensions to judge that tradeoff before export. An image cropper for printing should help you compare framing with realistic physical size, not imply that cropping creates extra image detail.
Some images should not be cropped at all. Collages, composites, scanned artwork, and layouts with captions, signatures, borders, or intentional edge details may use the outer area as part of the content.
If removing an edge changes the meaning, balance, attribution, or designed boundary, keep the full frame. Resize or upscale instead when the problem is output dimensions rather than unwanted composition.
The 1:1 preset locks a perfect square — the exact ratio profile photos, avatars, and square social posts need. Pick 1:1, drag the handles, and export at full resolution.
Flip the crop shape to circle for avatars and round badges. The export keeps a square canvas with transparent corners, so the round cutout stays clean on any background.
The editor runs in this browser tab. Open the page, drop a photo, crop, and download — the file never leaves your device.
Pick a JPG, PNG, or WebP file from your device. The browser reads its true pixel dimensions locally and initializes the crop frame to the complete source.
Move the crop box, resize it from a corner, choose a print ratio, or type exact X/Y/W/H pixels. The numeric controls and canvas stay synchronized.
Check cropped pixels, ratio, 300 DPI print size, and estimated file size. Then download the generated Blob or send that exact Blob into Rasterbator as a local draft.