SocialSizer Help

A complete guide to the social media image resizer, from the first picture to a ZIP of sixty.

Last Updated: October 6, 2026

Table of Contents

  1. Getting Started
  2. Adding Pictures
  3. Platform Sizes
  4. Custom and Recent Sizes
  5. The Preview: Zoom, Pan and Safe Zones
  6. Crop or Fit
  7. Format, Quality and Background
  8. Batches
  9. Export All Sizes and the ZIP
  10. Export Current
  11. Keyboard Shortcuts
  12. What Is Remembered
  13. Troubleshooting
  14. Support

1. Getting Started

1.1 What you need

1.2 The layout

The tool is one page in three panels. Platform Sizes on the left lists the seventeen presets by platform, with custom and recent sizes at the bottom. The Preview in the middle starts as a drop zone and shows the open picture once there is one, with zoom controls beneath and thumbnails when there are several pictures. Export Settings on the right holds the quality slider, the format, the background colour, the two switches and the list of selected sizes. The toolbar above holds Add Pictures, Select All, Clear and Shortcuts on the left, and Export Current and Export All Sizes on the right. On tablets the preview spans the top with the two lists beneath; on phones everything stacks.

1.3 Where your pictures go

Nowhere. The pictures are read by your browser, drawn at each size on an invisible drawing surface and saved from there to your downloads folder. Nothing is uploaded and there is no account. Only the export settings and the last five sizes you used are kept, in this browser.

2. Adding Pictures

Drop one or more files on the Preview panel, click anywhere in the drop zone, press Enter or Space on it, click Add Pictures in the toolbar, or press Ctrl+O. The first picture opens in the preview. Files that are not images are skipped, and a toast says how many were loaded. Once a picture is open, Add Pictures, Ctrl+O, the + thumbnail and a drop onto the preview all add to the set; Replace in the preview controls starts over with a new set.

3. Platform Sizes

Tick a size to select it; the row lights up, the count in the panel header changes, and the size appears under Selected Sizes on the right with a cross to remove it. Any number of sizes can be ticked. Select All (Ctrl+A) ticks every size in the list; Clear (Escape) unticks them all.

4. Custom and Recent Sizes

Under Custom Size, type a width and a height in pixels (1 to 8000 each) and click Add Custom Size or press Enter. The size is ticked at once and listed above the fields with its own checkbox, named "Custom 1200x1200". Recent Sizes lists the last five sizes you selected, presets and custom ones alike; a click selects one again, and a custom size that is no longer in the list is re-created.

5. The Preview: Zoom, Pan and Safe Zones

The picture opens fitted to the panel. The slider, the + and - buttons, the + and - keys and the mouse wheel zoom between 5 and 200 percent; dragging with the mouse or a finger moves the view; Fit (R) brings the whole picture back. Zoom and position change the preview only, never the export. The checkerboard behind the picture shows transparent areas.

With Show Safe Zones on and at least one size selected, a dashed white frame shows the part of the picture that the first selected size will keep (with Lock Aspect Ratio off, the whole picture). The inner green frame marks a 10 percent margin inside it, where platforms place profile pictures, buttons and captions. A label beneath names the size. Keep faces, logos and text inside the green frame.

6. Crop or Fit

The crop is centred. For a subject that is off-centre, crop the picture roughly first in any photo app, then resize it here.

7. Format, Quality and Background

8. Batches

With two or more pictures loaded, thumbnails appear under the preview with a count. Click one to open it in the preview; the cross on a thumbnail removes that picture; the + thumbnail adds more. Every setting applies to all of them, and Export All Sizes makes every selected size for every picture.

9. Export All Sizes and the ZIP

Export All Sizes (Ctrl+E) is enabled once a picture is open and a size is ticked. A progress window counts the files as they are made. One file downloads on its own, named after the picture and the size (holiday_1080x1080.jpg). Two or more are packed into a single ZIP named after the first picture, because browsers block a burst of separate downloads; inside, every file carries its picture's name and size. Ten pictures at six sizes make sixty files in one ZIP in a few seconds.

10. Export Current

Export Current (Ctrl+S) saves the open picture at its own pixel size, in the chosen format and quality, with the background colour behind any transparent parts. Use it to convert a PNG to a JPG, to shrink a photo's file size, or to flatten a transparent logo onto a colour. Pictures over 8000 pixels a side are refused; tick a size for those instead.

11. Keyboard Shortcuts

Single-key shortcuts do not fire while a field has the focus. The Shortcuts button in the toolbar shows the same list.

12. What Is Remembered

The export settings (quality, format, background colour, Lock Aspect Ratio and Show Safe Zones) and the last five sizes are kept in your browser's storage on this device and come back next time. The pictures and the selection are not; reloading the page starts fresh. Clearing the site's data removes the settings.

13. Troubleshooting

14. Support

Questions, problems and suggestions for new sizes go through the contact form. Say which browser and device you use and what you did before the problem appeared. Short answers to the most common questions are on the FAQ page.