A better beginning
A good photo gives each stitch a purpose.
Sharp eyes, soft light and a close crop usually matter more than a huge file. Your source image sets the limit on what the chart can keep.
Choose clarity over resolution
A face in focus at a modest resolution is more useful than a large blurred image. The maker accepts JPG, PNG and WebP up to 15 MB, 24 megapixels and 10,000 pixels on either side. Each side must be at least 32 pixels.
Fill the crop with your pet
Remove furniture and distant scenery from the rectangle before adding stitches. Leave space for ears. Check that important details occupy more than one cell after conversion.
Use even, natural light
Avoid harsh flash, deep eye shadows and filters that change coat color. Gentle brightness and contrast adjustments can help, but cannot restore missing detail.
Check direction and transparency
Modern browser decoding handles orientation metadata; inspect the result and rotate when necessary. Existing alpha transparency is preserved as empty grid cells below the opacity threshold. Partially transparent edge pixels are thresholded, so inspect edges. There is no automatic background removal.
Compare at the final grid size
View the entire portrait, then zoom into eyes and nose. If a feature disappears, crop closer or increase stitch width before increasing cleanup. Backgrounds count as stitches unless they are transparent or erased.