A social image does not need to look elaborate. It needs to survive the route from your editor to a small feed card without losing the point.
This six-step check is deliberately mechanical. Run it on the exported file, not only on the editable canvas.
1. Name the exact destination
“Social media post” is not a useful specification. Decide whether the asset is a single Instagram photo, a LinkedIn post image, an X header, a YouTube thumbnail, or something else.
Platforms accept different ratios, and one platform may accept several. Current official examples show why a single universal size chart is unreliable:
- Instagram retains photos at 1080 pixels wide when their ratio is between 1.91:1 and 3:4.
- LinkedIn accepts post photos from 3:1 through 4:5 and recommends a width of 1080 pixels.
- X displays a single photo in full when its ratio is between 2:1 and 3:4.
Those ranges come from the current Instagram photo guidance, LinkedIn photo requirements, and X photo help. Check the destination again when a campaign is reused later because platform rules change.
2. Verify the canvas before arranging anything
Write the width, height, and ratio in the brief. This catches a common failure: designing carefully on the wrong canvas and then forcing the layout into a different crop.
Image for Post currently offers four PNG layouts:
| Layout | Export size | Ratio |
|---|---|---|
| 1104 × 552 | 2:1 | |
| Square | 1080 × 1080 | 1:1 |
| X | 1600 × 900 | 16:9 |
| 1200 × 630 | about 1.91:1 |
Its video layouts are 1920 × 1080, 1080 × 1920, and 1080 × 1080. These are presets, not a claim that every platform placement is covered. If the destination requires another size, use an editor that can create that exact canvas.
3. Make one message win
At feed size, a viewer should be able to identify the subject and the main message without inspecting the image.
Try this test:
- Hide the caption.
- View the image at roughly the width it will occupy on a phone.
- Ask what the eye reaches first.
- Remove or reduce anything competing with that first point.
A logo, headline, photo, badge, date, and call to action can all be legitimate. They should not all have equal weight. Use size, position, spacing, and contrast to establish an order.
4. Test the smallest likely rendering
Zooming out in an editor is not the same as seeing the exported file in a feed. Export once, open the file, and make it small.
Look specifically for:
- text that requires effort to read;
- a face, product, or diagram cropped too tightly;
- thin lines that disappear after compression;
- a call to action that looks like decorative text;
- details placed so close to an edge that a different preview could trim them.
If an image only works when enlarged, simplify it. Moving one sentence into the post caption is often better than reducing the type.
5. Check contrast and write the alt text
Contrast is not a style preference when it determines whether the message can be read. Test text against the part of the image where it actually sits. A translucent overlay or a quieter crop can be more reliable than adding an outline around every letter.
Then write the alternative text before publishing. Describe the information the image contributes, not every decorative detail. If the image contains essential words, include their meaning in the post text or alt text as appropriate.
LinkedIn exposes an ALT control in its photo workflow, and X documents image descriptions as an accessibility feature. Treat that field as part of publishing, not an optional cleanup task.
6. Inspect the real export
Check the file that will be uploaded:
- confirm the pixel dimensions;
- confirm the file type and size;
- look for blurred type or colour banding;
- make sure no private notes, hidden layers, or placeholder text appear;
- preview it in the platform composer before posting.
The composer is the last reliable place to catch a crop or multi-image arrangement that differs from the editor. Do not publish solely because the source canvas looked correct.
A repeatable two-minute preflight
Use the same order every time:
- Destination and placement.
- Canvas dimensions and ratio.
- One dominant message.
- Small-size readability.
- Contrast and alt text.
- Export and composer preview.
The checklist cannot promise reach or engagement. It can prevent avoidable production errors.
Open Image for Post if one of its supported layouts fits your destination. You can customise and export a PNG or MP4 in the browser without signing up. An account is only needed for cloud sync and AI text features.
Sources checked
- Instagram Help: photo resolution and aspect ratio
- LinkedIn Help: sharing photos
- X Help: posting photos or GIFs
Platform documentation and the Image for Post application were checked on 29 July 2026.