Adjusting SNS image size: Post/story ratio and how to use cropping/margin

Select preset for square/vertical posts/stories

The tool provides thumbnail sizes of 1080×1080 square, 1080×1350 vertical post, 1080×1920 vertical cover, 1200×630 horizontal shared image, and 1280×720 video thumbnail. If the horizontal and vertical pixels are expressed as a ratio, they are 1:1, 4:5, 9:16, 40:21, and 16:9, respectively.

These values ​​are presets to quickly start production. This is not an official recommended standard for all posting locations on a particular SNS, nor is it a list that guarantees successful uploads. They may be truncated differently in your feed, profile grid, and preview cards, so check your publishing app's current instructions and final preview. This tool creates photo files and does not post videos or stories directly.

Steps to create photos for SNS posting

1. Select PNG·JPEG·WebP photos.
2. Select the preset that matches the image you want to publish.
3. Choose the placement method: Fill Screen or Fill All.
4. Move the horizontal and vertical positions so that the face, product, or text remains in the required position.
5. Select the background color to use for the margins and transparent areas.
6. Select the storage format and quality, create the image, and download it.

A position value of 0 is aligned based on the left/top, and 100 is aligned based on the right/bottom. If there is no truncation or margin on that axis, the shape will not change even if you change the position of that axis. If you change the settings, previous download results will be erased, so you will need to click Create Image again.

What is the difference between screen fill and full fill?

Screen fill enlarges and reduces the target canvas to completely cover it, and cuts off the part that goes outside the canvas. Insert All fits the entire image and fills the remaining area with the background color. Both methods maintain the proportions of the photo.

For example, if you place a 1600×900 landscape photo entirely on a 1080×1920 canvas, the photo itself will be drawn in an area of 1080×607.5, leaving margins at the top and bottom. The screen fill is set to height 1920, so the left and right sides are cut off significantly. For photos where faces, product edges, or existing text are important, compare the two methods before choosing.

The tool redraws the image onto the browser Canvas. The original file is not overwritten and is saved with the selected background color. Transparent areas in PNG input are also filled with the background color, so this is not a function that leaves transparency in the results.

Select JPEG quality 75·85·95 and PNG·WebP

For photos, use JPEG quality 85 as a starting point and compare the resulting capacity and compression traces. 75 may help reduce capacity with stronger compression, but may increase traces around letters and outlines. 95 can create larger files for more detail. Quality values ​​do not imply preservation of a percentage of the original image quality, nor do they guarantee exact file size.

PNG stores processed pixels losslessly, so they can be compared on images with text or lines. However, it does not restore information that has already been cut or reduced to its original state. Check with the service you are using to see whether WebP uploads are allowed. When selecting PNG, quality settings do not apply.

Batch preview is canvas before compression. Please check the actual image quality and capacity after compression with the downloaded file. If you have file size limitations, you can continue to use the image size reduction tool. Images may appear differently after upload as the publishing service reprocesses them.

Technical Notes: MDN Canvas image placement, Canvas image saving and quality settings.

Enlarging small originals and items to check before posting

This tool saves at the exact pixel dimensions of the selected preset. Even small photos can be enlarged, and instructions will be displayed if enlargement is necessary. Increasing the number of pixels does not restore detail that was missing from the original. If possible, use originals of sufficient resolution.

Input is 20MiB per file, 16 million pixels, and no more than 8192px on each side. Animation files are processed as a single still image, and HEIC and SVG files are not supported. Check the download results for important photos, as the browser resaves them in the orientation and colors they were read from.

Make sure the face and product are not cut off, the text is not too close to the edges, or is not obscured by buttons or descriptions in the publishing app. This tool does not automatically calculate SNS-specific interface safe areas. If you want to add text or a logo, you can edit it in the photo editing tool and then resize it.

Frequently Asked Questions