Make post photos 1080 × 1350 (4:5) for X and LinkedIn, and 1080 × 1920 (9:16) for TikTok. For profiles, use a 1500 × 500 header and a 400 × 400 photo on X, a 1584 × 396 background and a 400 × 400 photo on LinkedIn, and a square photo on TikTok, which has no banner. The rest of this page has each network's limits, and what each feed cuts off.
Each network's own help pages and developer docs were checked on October 26, 2026. They're linked beside the claims and under Sources. Where a network doesn't document how its feed crops, this page says so and gives what Flaghand measured on the live site instead, with the date. X's Help Center answered our check with a bot challenge, so nothing here is quoted from it. X's limits come from its developer docs.
The sizes at a glance
| X | TikTok | ||
|---|---|---|---|
| Post photo | 1080 × 1350 (4:5) | 1080 × 1350 (4:5) | 1080 × 1920 (9:16) |
| Photos in one post | Up to 4 | Up to 20 | Up to 35 |
| Photo files | JPG, PNG, GIF or WEBP, up to 5 MB | Up to 5 MB; JPG, PNG or GIF through the API | JPEG or WebP, up to 1080p and 20 MB, through the API |
| Documents | None | PDF, PPT, PPTX, DOC or DOCX, up to 100 MB and 300 pages | None; photo posts instead |
| Profile photo | 400 × 400, shown as a circle | 400 × 400 to 7680 × 4320, PNG or JPG, up to 8 MB | At least 20 × 20, shown as a circle |
| Banner | 1500 × 500 (3:1) | 1584 × 396 (4:1); a Page's cover is 1512 × 256 | None |
The post photo shapes, X's two profile sizes and TikTok's 9:16 are this page's picks, from what each feed draws (below). Every other number is the network's own.
The free image size checker draws your own photos, banner and profile photo the way X and LinkedIn lay them out, on desktop and on a phone, and says what's cut. Nothing is uploaded.
X
Post photos
- Up to 4 photos, 1 animated GIF or 1 video in a post (X's media docs).
- JPG, PNG, GIF or WEBP, up to 5 MB. An animated GIF can be 15 MB. X's media best practices add that a GIF does best at 1280 × 1080 or smaller and 350 frames or fewer.
- Alt text is up to 1,000 characters (media metadata).
- X has no document posts. Several photos in one post are its carousel.
How X crops photos in the timeline
X's docs don't say how the timeline crops. This is what x.com drew when Flaghand measured it for its previews, the same layout the image size checker draws:
- One photo is shown whole, at its own shape across the column. A photo taller than the column allows is shown narrower, not cut.
- Two photos sit side by side, each whole, when they fit the row at about 200 px tall on desktop. Otherwise, and for 3 or 4 photos, the set scrolls sideways at one height.
- In a set, square and taller photos keep their shape. A photo wider than 20:17 (about 1.18:1) can lose its sides.
So a 4:5 or square photo is never cut, alone or in a set. Check yours in the image size checker.
Profile photo and header
X's developer docs don't list profile photo or header sizes, and its Help Center didn't load for our check. What x.com draws, measured on October 25, 2026 at 600 px (desktop) and 390 px (an iPhone's width):
- The header spans the profile column at 3:1. A 1500 × 500 image is 3:1 at 2.5 times the 600 px desktop column.
- The profile photo is a circle up to 136 px across, 16 px from the left, its centre on the header's bottom edge. It covers part of the header's bottom left, so keep text and faces out of that corner.
- Use 400 × 400 for the photo, and keep what matters away from its corners, which the circle hides.
The checker's profile view shows your header and photo together on desktop and on a phone.
Post photos
From LinkedIn's help page Share photos on LinkedIn:
- Up to 20 photos in a post, and 5 MB a photo.
- At least 552 × 276; LinkedIn recommends 1080 px wide.
- 3:1 to 4:5. A photo wider than 3:1 is centred and cropped to fit.
- A post has a link or photos, not both. Photos can't be resized or edited after posting.
LinkedIn's Images API takes JPG, GIF and PNG under 36,152,320 pixels, a GIF up to 250 frames, and alt text up to 4,086 characters (LinkedIn recommends under 120). Its MultiImage API takes 2 to 20 images.
How LinkedIn crops in the feed
- One photo shows across the post at its own shape, never taller than 4:5. A taller photo is shown whole in a 4:5 box, with bars at its sides. That's the 4:5 limit in LinkedIn's help, as Flaghand's measured preview draws it.
- Several photos: LinkedIn's help, last updated two years ago, describes a grid. Two photos sit side by side, keeping their shapes. With 3 or more, the first photo sets the layout: a landscape one goes on top with the rest below, and a portrait or square one goes on the left with the rest stacked beside it. The whole set is at most 4:5, and photos in the bottom row can be cropped.
- What Flaghand measured on linkedin.com for its previews, and the checker draws, is different: several photos scroll sideways as frames of one size, each photo cut to fill its frame.
Either way, a photo alone is the only one sure to be shown whole. See yours in the image size checker or the LinkedIn post preview.
Documents: LinkedIn's carousels
A swipeable LinkedIn carousel is a document post: one file whose pages people swipe through. From LinkedIn's document help and its document FAQ:
- PDF, PPT, PPTX, DOC or DOCX, up to 100 MB and 300 pages. LinkedIn suggests converting to PDF for the best quality.
- One document a post, with a title. You can edit the title and the post's text later, not the file.
- Every page the same size. A PDF with pages of different sizes must be fit to one size, and a layered PDF flattened. Videos and animations show as still images.
- People who can see the post can download the document as a PDF.
LinkedIn's help gives no page size. Its photo rules stop at 4:5, so 1080 × 1350 pages match the tallest shape it shows a photo. The Documents API has the same file types and limits.
Profile photo and background
From LinkedIn's help page Photo won't upload to your profile:
- Profile photo: between 400 × 400 and 7680 × 4320.
- Background photo: 1584 × 396 is recommended.
- PNG or JPG, up to 8 MB. LinkedIn's help says it doesn't take GIFs.
LinkedIn shows the background at 4:1 across the top of the profile, with the round profile photo over its left side. On an iPhone the photo covers most of the background's height there. Those positions come from LinkedIn's own screenshots of its apps. Keep the background's text to its right and centre. Try both in the checker's profile view.
LinkedIn Pages have their own sizes (Page image specifications, updated two months ago): a 400 × 400 logo (at least 268 × 268) and a 1512 × 256 cover, PNG or JPEG, up to 3 MB. The cover can be trimmed to fit the screen, so keep key details away from its edges, especially the lower right. The logo is shown on light and dark backgrounds, and a transparent one on white. The checker draws personal profiles, not Pages.
TikTok
Photo posts: TikTok's carousels
TikTok's Help Center has no article on photo sizes; its search found none on October 26. The limits below are from TikTok's developer docs for its Content Posting API, which is how apps post for you:
- Up to 35 photos in a post (photo post reference).
- JPEG or WebP, up to 1080p and 20 MB each (media transfer guide). A PNG has to be converted first.
How TikTok shows photos
TikTok's docs don't say. What Flaghand measured, logged out on tiktok.com on October 24, 2026:
- The desktop feed is a 9:16 card on black. A photo of another shape gets black bars rather than being cut. Opened on its own page, the card takes the photos' shape instead.
- In TikTok's phone layout (its mobile site at an iPhone's 390 px), a photo spans the screen's width at its own shape: a 2:3 photo is 390 × 585, and a 9:16 one fills 390 × 693.
- The caption, @handle and buttons sit over the photo: the buttons up the right edge, the text at the bottom left. Keep words and faces out of those areas.
So 1080 × 1920 is the size to make: the feed's own 9:16 shape, at the largest size 1080p allows. The free TikTok slideshow maker puts text on photos and saves each slide at 1080 × 1920 as a PNG, ready to post from your phone. Convert them to JPEG or WebP if an app will post them through the API.
Profile photo
TikTok's help page on adding a profile photo says a photo must be at least 20 × 20 pixels, and that you crop it after choosing it. A profile video replaces the photo. TikTok shows the photo as a circle. It gives no recommended size, so the same 400 × 400 square you use elsewhere works. TikTok profiles have no banner.
Ads use their own specs
Paid posts follow each network's ad specs, not the organic sizes above:
- LinkedIn single image ads (LinkedIn's ad specs): JPG, PNG or GIF up to 5 MB, at 1200 × 628 (1.91:1), 1200 × 1200 (1:1) or 720 × 900 (4:5). Vertical images serve only on mobile.
- TikTok carousel ads (TikTok's ad specs): a standard carousel takes 2 to 35 images, JPG or PNG, at 1200 × 628, 640 × 640 or 720 × 1280.
- X ad card images (X's Ads API docs): at least 800 px wide and up to 3 MB, as BMP, JPEG or PNG, at 1:1 or 1.91:1 for a website card. X's business site, which has its other ad specs, didn't load for our check.
What Flaghand adds
Flaghand is a publishing desk where your AI agent drafts posts and you approve them. It shows each X and LinkedIn post the way the feed lays it out, with the same renderers as the image size checker, and its check before approval flags anything that wouldn't post exactly as previewed, media counts and sizes included. It takes JPEG, PNG, WebP and GIF photos, and PDF documents for LinkedIn, up to 50 MB. A document's pages are previewed before you approve it.
No agent token can approve, schedule or post: you approve the exact post in the desk with a passkey. Flaghand doesn't offer TikTok scheduling yet. Every media field is in Flaghand's drafts and media docs. Sign-up isn't open yet: get access to Flaghand.
Sources
All read on October 26, 2026. X's Help Center and business site answered with a bot check, which wasn't bypassed.
- X: media, media best practices, media metadata (alt text), Ads API creatives
- LinkedIn Help: share photos, profile photo upload, documents, document FAQ, Page images, single image ads
- LinkedIn API, version 202610: Images, MultiImage, Documents
- TikTok: adding a profile photo, photo post reference, media transfer guide, carousel ad specs
- Flaghand's measurements: x.com's profile on October 25, 2026, tiktok.com's feed and phone layout on October 24, 2026, and the X and LinkedIn post layouts its previews and the image size checker draw.