How to crop an A4 shipping-label PDF to 4×6 on iPhone

Thermal label printers for parcels use labels that are 4 × 6 inches, or about 100 × 150 mm. In the UK you’ll often see the same size called 6×4. A4 is 210 × 297 mm, so it’s roughly twice as wide and twice as tall.

Many carriers and marketplaces lay out a label PDF for A4 paper. The label itself takes up part of the page, and the rest is blank space, instructions, a packing slip or a second copy. Send that page to a 4×6 printer and you’ll usually get a tiny label, a cropped one, or a long strip of blank labels.

What you want is the label on its own, upright, filling a 4×6 page. That’s a crop, not a resize of the whole sheet.

Before you crop anything, look at where the label came from. Some services can give you a label-printer format directly. Royal Mail’s Click & Drop has a 6×4 label setting, Evri offers a thermal-sized label for parcels booked with it directly, and eBay offers a 4×6 format for some postage services. If the source can make a 4×6 label, use that. It’s the most reliable option.

Cropping helps when there’s no such option: labels that only download as A4, labels you’ve been sent by someone else, labels on a page with return labels or instructions, and screenshots.

Label Fixer imports from the Files app and from Photos, so the first job is to get the label into one of those.

• A PDF in an email: open the attachment, use the share button and choose Save to Files.
• A PDF in a website or app: when the PDF opens, use the share option to save it to Files. The wording varies from app to app.
• Only a screenshot or photo: that works too, and it’ll be in Photos. A PDF is better if you can get one, because it stays sharp. A screenshot can only be as sharp as your screen.

1. Open Label Fixer and import the label PDF from Files, or choose a screenshot or photo from Photos.
2. If the PDF has more than one page, pick the page with the label on it.
3. Label Fixer finds the label and crops it to a portrait 4×6 inch PDF. Check the preview: the address, barcode and any QR code should all be inside the crop.
4. If the crop has picked up too much, such as printed instructions beside the label, tap Edit Label. Move or resize the crop so it sits around the label, and rotate it if the label is sideways.
5. Share the finished PDF to your printer’s own app, or save it to Files, send it by Mail or AirDrop it to a computer that’s connected to the printer.

• Start from the original PDF. Label Fixer keeps the output vector-sharp where the source allows, so text and barcodes from a PDF stay crisp at any size.
• Keep the whole barcode. When you adjust the crop, leave a little space around barcodes and QR codes. A barcode cut off at the edge may not scan.
• Upright is right. The output is a portrait 4×6 page. If the label on your A4 page is sideways, rotate it in Edit Label so it reads the right way up.
• Don’t rescue a blurry photo. If the source is a low-resolution or heavily compressed image, cropping can’t add back missing detail. Get the original PDF if you can.

Most 4×6 thermal printers either come with their own iPhone app or work with AirPrint. If your printer has its own app, share the PDF to it from Label Fixer. If you print from a computer, save the PDF to Files or AirDrop it across.

• Choose 4×6 inch (sometimes listed as 6×4, or 100 × 150 mm) as the paper or label size in your printer’s app.
• Print at actual size or 100%. Avoid “fit” or “scale” options unless your printer’s instructions say otherwise.
• Do one test print when you set up a new printer or a new roll, and check the barcode is sharp, complete and not cut off at the edges.

Finished labels are kept in History, so if a parcel needs a second label or a print didn’t come out right, you can reopen and share it again without starting over. Everything stays on your device: there’s no account and nothing is uploaded.

The first five labels are free. Pro is a one-time purchase for unlimited labels, full history and bulk export from History.