A Dossier on What Instagram, X, LinkedIn, and Facebook Actually Do to Your Photo

Every major platform tells a version of the same lie: upload your image, and it'll look the way you sent it. None of them work that way. Every one of the four platforms below re-encodes every image that comes through their upload pipeline, on their own servers, using their own compression settings, regardless of how carefully you exported the original. The real question isn't "which format is best." It's "which format survives a second, mandatory compression pass without falling apart." Here's what's actually known about how each platform runs that pass, and what to feed it going in.

The one rule that applies before any of the platform-specific ones

Export in sRGB, always, no exceptions. This matters more than format choice on every platform below. Modern cameras and editing software often default to wider color spaces, Adobe RGB, Display P3, ProPhoto RGB, capable of representing more colors than a standard screen can show. Every platform here assumes sRGB and either strips or mismaps anything else on upload, which is exactly why a photo that looked vivid in your editor sometimes comes out dull and washed out the moment it's live. This single setting, checked once in your export dialog, prevents a specific and very common complaint before it happens.

Instagram

Recompression trigger: Two separate passes, not one. The first triggers if the image is wider than 1080 pixels, downscaling before anything else happens. The second triggers independently if the JPEG file exceeds roughly 1.5 MB, even if the dimensions were already correct. Either condition alone is enough to trigger extra compression on top of what's coming regardless.

Survives best as: A JPEG exported at exactly 1080px on the shorter dimension (1080×1350 for portrait feed posts, 1080×1080 for square), sRGB, and counterintuitively not at 100% quality. Exporting at 85-90% quality keeps the file small enough to dodge the second compression trigger, while a 100%-quality export often produces a larger file that gets hit harder by Instagram's own re-encoding. Either way, expect the platform to re-encode the image again at roughly 70-75% JPEG quality regardless of what arrives.

The mistake almost everyone makes: Uploading the largest, highest-quality export possible on the assumption that more quality in means more quality out. On Instagram specifically, that assumption backfires, a smaller, well-compressed file frequently survives the platform's own compression better than an oversized "perfect" one.

One quirk worth knowing: Instagram's mobile app handles WebP inconsistently. Stick to JPEG or PNG for predictable results across devices, even though WebP works fine as a format elsewhere.

X (formerly Twitter)

Recompression trigger: Aggressive re-compression kicks in specifically on images above roughly 5 MB, and the platform's own compression at that point tends to be heavy-handed rather than proportional to how far over the limit you are.

Survives best as: Pre-compressed before upload rather than left to the platform's discretion, a JPEG under 1 MB at 85-90% quality, exported in sRGB, generally produces a cleaner final result than uploading a large original and trusting X's compressor to make the right call.

The mistake almost everyone makes: Treating the 5 MB figure as a target to stay just under, rather than a threshold to stay well clear of. The closer a file sits to that limit, the more of X's own aggressive recompression logic ends up engaged.

One quirk worth knowing: Unlike Instagram, X does accept WebP, so it's a legitimate option here specifically if file size is the priority, one of the few platforms in this list where that's true.

Recompression trigger: Similarly aggressive on oversized files, though LinkedIn's specific thresholds are less publicly documented than Instagram's or X's. The safe assumption, treating any upload over a few megabytes as a candidate for heavy recompression, holds here as it does elsewhere.

Survives best as: sRGB JPEG or PNG at a size already close to the platform's display dimensions, LinkedIn's personal profile banner, for instance, has a specific 1584×396 spec, and matching that ahead of time avoids both an unnecessary crop and a resize-triggered quality hit.

The mistake almost everyone makes: Reusing a banner or post image exported for a different platform's aspect ratio and letting LinkedIn crop it automatically. The crop rarely lands where the original composition intended.

One quirk worth knowing: LinkedIn's professional-network context means text-heavy graphics, slide exports, quote cards, show up constantly. PNG holds sharp text through recompression noticeably better than JPEG does on this specific kind of content, worth the larger file size for anything with readable text in it.

Facebook

Recompression trigger: Facebook explicitly documents a preference for small, pre-optimized files over large ones for its cover and profile image slots specifically, an sRGB JPEG under 100 KB for a cover photo is officially recommended for the fastest load, well below what the platform would technically accept.

Survives best as: A modestly sized sRGB JPEG rather than a large, uncompressed original, particularly for banner and cover positions where Facebook has published specific pixel dimensions (851×315 for a desktop cover photo) that are worth matching exactly rather than approximating.

The mistake almost everyone makes: Uploading a cover photo sized for a different platform's banner ratio and trusting Facebook's crop to preserve the important part of the image. Match the platform's actual published dimension instead of guessing.

One quirk worth knowing: Facebook's recompression is generally gentler on PNG graphics and logos than on JPEG photographs, consistent with the pattern across every platform here: flat-color, sharp-edged content tends to survive a second compression pass with less visible damage than continuous-tone photography does.

If you only want one export that works everywhere

A 1080×1080 pixel square, sRGB JPEG at roughly 85-90% quality, under a couple of megabytes, displays without cropping on Instagram, Facebook, X, and LinkedIn alike. It won't be the ideal aspect ratio for any single platform's best-performing format, portrait tends to outperform square on Instagram specifically, but it's the one export that survives every platform's recompression pass reasonably well without needing four separate versions of the same image.

The pattern underneath all four dossiers

Every platform above runs the same basic play: accept the upload, re-encode it under the hood, and show you the result, not your original file. The specific thresholds differ, but the underlying advice doesn't: export in sRGB, keep the file meaningfully smaller than whatever limit is published, and don't assume a "perfect" maximum-quality export beats a well-compressed one, since on most of these platforms, it doesn't. Prepare and pre-compress your social media assets directly in your browser with our converter.