How to Crop an Image to Any Size (Use-Case Guide)

Cropping looks simple until you need a specific size. A profile picture needs a perfect square. A passport photo has hard millimeter requirements. An Instagram post expects 4:5. Get any of these wrong and you end up rejected by the form or stuck with awkward white bars.

This guide is organized by use case. Each section gives you the exact ratio or pixel size, plus one tip to avoid the most common mistake.

How to Crop in Filuni (the basics — read once)

Open the crop an image tool and upload your file (JPG, PNG, WebP, and most common formats are accepted). You can type exact pixel dimensions, or lock an aspect ratio and drag the crop box freely. The tool runs client-side — your image never leaves your browser. Hit Download when the preview looks right.

That's it. The sections below just tell you what numbers to type for each scenario.

For a Profile Picture (1:1 Square)

Almost every platform — Twitter/X, LinkedIn, Discord, WhatsApp — displays profile photos as circles or squares. The safe bet is a 1:1 ratio at a resolution large enough to look sharp when scaled down. A good target is 800×800 px; that's more than enough for any profile thumbnail and keeps the file under 200 KB as a compressed JPG.

When you set the ratio to 1:1, center the crop box on the subject's face and leave some headroom above the head. The most common mistake is cropping too tight — platforms often re-crop on upload, so a little breathing room saves you a second edit.

Tip: If your subject is off-center, drag the crop box to where the face actually is. The 1:1 constraint doesn't force you to use the middle of the canvas.

For Social Media Posts (4:5, 1.91:1, 9:16)

Social platforms are picky, and the right ratio depends on the placement:

• Instagram feed (portrait): 4:5 — this fills more screen on mobile and typically earns better engagement than a square. At 1080×1350 px you're at native resolution.
• Instagram/Facebook landscape or link preview: 1.91:1, typically 1200×628 px. The same size works for Open Graph (og:image) tags if you're a developer.
• Instagram Reels cover / TikTok thumbnail / Pinterest: 9:16, the full vertical phone screen. 1080×1920 px is the standard.

The main thing to watch with 9:16 is that most cameras shoot 4:3 or 3:2, so you will lose content on the sides. Crop around the focal point, not the center of the canvas.

Tip: For a post that also needs to work as a Story, crop 4:5 first, save it, then re-crop the original at 9:16. Two crops from one source keeps the look consistent.

For Printing (4×6, 5×7, A4)

Print sizes are given in inches, but your cropper works in pixels, so you need to know the DPI (dots per inch) you're printing at. Standard photo prints are 300 DPI. The math is straightforward:

• 4×6 inch print at 300 DPI: 1200×1800 px
• 5×7 inch print at 300 DPI: 1500×2100 px
• A4 (8.27×11.69 inch) at 300 DPI: 2481×3507 px

If your original is smaller than these numbers, don't upscale — printing an upscaled image produces a blurry result. Crop to the correct ratio and let the print lab handle scaling from there.

Tip: A 4×6 print is a 2:3 ratio (matching most camera sensors), so a straight-from-camera JPG loses very little. A 5×7 is 5:7 — slightly narrower — so expect to trim a sliver off the long sides. Check the preview before downloading.

For a Passport or ID Photo

Passport specs vary by country but follow the same pattern: fixed print size, fixed pixel resolution, and a rule about how much of the frame the head must fill. The US requires 2×2 inches (600×600 px at 300 DPI) with the head between 1 and 1.375 inches tall. Both the UK and EU use 35×45 mm with their own head-height tolerances.

For most submission forms, a 600×600 px JPEG with the head centered and occupying roughly 70–80% of the frame height will pass automated checks. Set the crop to 1:1 in the Filuni cropper, frame the chin near the bottom, and leave a small gap above the head — do not cut off any hair.

Tip: Passport photos require a plain white or off-white background — the cropper handles framing, not background color. If your photo was shot against a cluttered wall, run Filuni's background-removal tool first, then crop the result.

FAQ

Does cropping reduce image quality?

No — cropping only removes pixels outside the selection. Quality loss happens if you then upscale the result beyond the original dimensions. Crop to a size equal to or smaller than the source and the remaining pixels are untouched.

What file formats does the Filuni cropper accept?

JPG, PNG, WebP, and GIF. The output downloads in the same format as the input. If you need a format change, run the image converter tool afterward.

Can I enter a custom ratio like 3:2 or 16:10?

Yes. Type any width and height values directly into the dimension fields instead of choosing a preset. No restriction on the ratio.

Is there a file size limit?

The cropper runs entirely in your browser, so the limit is your device memory, not a server cap. Most laptops handle images up to 20–30 MB easily. For very large files, export a JPG from your source first to keep things fast.