Image Formats and Settings for Social Media Uploads

What platforms do after you press upload

Large platforms typically resize your image to a set of display widths and re-encode it with their own compression settings, which you cannot see or change. They also tend to drop metadata such as GPS location from the public copy, though that is no substitute for removing it yourself.

Two consequences follow. First, anything beyond the display size is wasted, because the platform throws it away. Second, the platform's pass is lossy, so a file that was already heavily compressed gets compressed again and shows blocky artifacts around text and edges. A clean upload copy beats a large messy one.

Numbers you can check, and numbers you should not trust

Instagram's Help Center page on the resolution of shared photos mentions 1080 by 1080 pixels as the upper figure for photos it uploads. That page is short, and platform requirements change often, so treat 1080 pixels as a rule of thumb for the width of a feed image and check the current requirements in the upload screen or the platform's help pages. I did not find official pages that give one consistent set of formats and dimensions across platforms, which is why you will see conflicting numbers on third-party cheat sheets.

The pixel arithmetic is safe regardless of the platform. A 4032 by 3024 photo displayed at 1080 pixels wide becomes 1080 by 810, which is 0.87 megapixels out of the original 12.19, or about 7 percent of the pixels. The platform discards the other 93 percent, so sending all of them only slows the upload.

Posting a photo

What to upload: a JPEG in the sRGB color space, resized so that its width matches what the platform displays (1080 pixels is a reasonable rule of thumb for a feed image), with the quality at a normal setting rather than a low one. The aim is that the platform's re-encoding is the only heavy compression the picture ever goes through.

What to avoid: shrinking the picture to a tiny size with a very low quality setting before upload. You would get compression damage twice, and the second pass tends to amplify blocks from the first. If your photos are HEIC, convert them first, because many upload forms reject the format; see the comparison of HEIC and JPEG.

Posting a graphic with text

Announcement cards, quote images and infographics contain flat colors and sharp lettering, which suffer most from re-compression. Upload a PNG at the final display size, since the platform resizes it anyway. Avoid saving the graphic as a low-quality JPEG first; faint speckles appear around letters and are then compressed again.

If the platform converts everything to JPEG anyway, the PNG still gives it the cleanest starting point.

Profile pictures, logos and transparent images

Profile photos are usually cropped to a circle or square and displayed small, so a square image of about 1000 pixels is generally ample (check the size the platform states), and the details of the crop are controlled in the platform's own editor, not in this converter. For a logo with a transparent background, check whether the platform preserves transparency at all. Some fill transparent areas with white or black, which can ruin a dark logo.

The safe route is to decide the background yourself. Convert the logo to JPEG on a background color that matches the profile frame, which is covered in the background color article, and upload the result as a plain opaque image.

One photo prepared for three destinations

Say you start with a 6000 by 4000 pixel photo, 24 megapixels. For a feed post you export a JPEG 1080 pixels wide (1080 by 720, 0.78 megapixels, about 3 percent of the original pixels). For a blog you keep 1600 pixels. For a printed flyer you keep the full file. Three exports from one source, each sized for where it goes, give better results than one medium-sized file reused everywhere, and each export starts from the original rather than from the previous export.

The same principle is why the files you upload should come from your best copy. A picture that has been saved, messaged, downloaded and saved again has already lost detail before the platform touches it. Each extra lossy pass removes a little more.

Why the same image looks different from app to app

Each platform runs its own encoder at its own strength, and each app draws the result on screens with different color handling. Phone photos in a wide-gamut color space can look flatter or shift in color when a platform converts them to sRGB, which is the standard assumption of the web. If color matters, as it does for brand colors or product photos, deliver sRGB yourself, using the color profile guide to understand what changes, so the platform has nothing left to guess.

Animated images, screenshots and memes

Animated GIFs and animated WebP files may be converted to video by the platform or rejected, depending on where you upload. If you convert one in this tool you get a still image of the first frame, not an animation. Screenshots follow the same rule as text graphics: PNG at native size. Memes that have been saved and re-shared many times are the typical victims of stacked compression, which is why they look worse each time; a fresh export from the source is always better than another screenshot of a screenshot. The same applies to your own work: keep exporting from the master file, not from the last version you posted.

Checking an upload, and what to do when it is refused

Before you post, open the file you are about to upload, not the one on your camera roll, and zoom to 100 percent on a detailed area such as text or a face. If edges look blocky or speckled there, they will look worse after the platform recompresses them. A second look at the file size also helps: an image of 1080 pixels width that weighs several megabytes was probably saved at a needlessly high quality, and a few hundred kilobytes usually signals a lean, clean copy, though the right figure varies with the picture.

If the platform shows an error rather than a blurry result, the cause is usually the file itself: an unsupported format, a size over the limit, or a file whose contents do not match its extension. Go through the steps in the guide to rejected image files; most failures turn up in the first three checks.