Resize Image to A3 Size
without uploading it.
Get a photo or poster to A3 print size — 3508×4961 pixels at 300 DPI — so it prints sharp at full poster scale.
Drop an image, or click to browse
Drop your image — A3 print size (3508×4961) is pre-selected.
Click "Resize image".
Download and send it to print.
Why there's no upload step
A3 paper is 297×420mm, which at the professional print standard of 300 DPI is exactly 3508×4961 pixels — twice the area of A4, so it needs a high-resolution source to stay crisp at poster size. A3 has the same 1:1.414 ISO shape as A4; this tool preserves your image's aspect ratio and fits it inside the A3 frame rather than stretching it.
Is my image uploaded anywhere?+
No — resizing happens entirely in your browser.
Why 3508×4961 pixels?+
That's A3 (297×420mm) at 300 DPI — the resolution a print shop needs for a sharp large-format print.
Will my image be stretched to A3?+
No — aspect ratio is preserved. It's fit inside the A3 frame at the largest size that doesn't distort it.
My source photo is small — will it still be sharp?+
A3 is large, so a low-resolution source may look soft. Start from the highest-resolution original you have.