Performance
Performance guidance for large images and multi-page designs.
The image editor runs in the user's browser, so the size of the pictures and the number of pages decide how much memory and time it needs. This page lists the limits, and the settings that keep designs small.
Large images
The editor accepts a picture of any size. It keeps the whole file in the browser while the user works, and scales it only on the page.
Without onUploadAsset, a saved template holds its pictures inside it. A template with a picture larger than 1 MB, or with more than 5 MB of pictures in total, makes the console warn about the size. Pass onUploadAsset, so that pictures go to your storage and the template holds only their addresses. See Asset storage.
A picture from your storage or from a stock service is downloaded once, and it must allow cross-origin requests.
Exported files have these limits:
| Export | Largest size |
|---|---|
| PNG, JPEG | 6000 × 4000 pixels. The pixel ratio stops at the value that keeps the page within this size. |
| The page fits A4. At 300 DPI, a square page holds 2480 × 2480 pixels. |
The export draws the page from the design, not from the screen. The size of the browser window does not change the file.
Page count
A design has at most 10 pages. The editor keeps every page in memory, and shows one page at a time.
An export of several pages draws the pages one after another, so it takes longer with more pages. While it works, the editor shows "Preparing your pages". In a test on a desktop computer, with one picture on each page:
| Export | 1 page | 10 pages |
|---|---|---|
| PDF, 300 DPI | 0.5 seconds | 2.8 seconds |
| PNG, as a ZIP file for 10 pages | 0.4 seconds | 0.9 seconds |
These times depend on the device and on the content of the pages.
To keep a large design fast, split it into several designs, and use templates for the parts that repeat. See Templates.