PostDecks
PostDecks

Caption limits and image sizes, checked against every format the tool renders.

Social media character limits and image sizes

Every platform accepts a different caption length, cuts it off at a different point, and crops your image to a different shape. The table below is the full set for the ten formats PostDecks renders, including where each one truncates, which is rarely where you would guess.

Last checked . These numbers come from the same source that drives the preview tool, so if one were wrong the previews would be wrong with it.

Every platform at a glance

PlatformCaption limitCuts off atImage size
X (Twitter)280Shows in full1600 × 900 · 16:9
LinkedIn3,000~2101200 × 627 · 1.91:1
LinkedIn Carousel3,000~2101080 × 1080 · 1:1
Instagram2,200~1251080 × 1440 · 3:4
Instagram StoryNo caption1080 × 1920 · 9:16
Facebook63,206~4771200 × 630 · 1.91:1
Facebook StoryNo caption1080 × 1920 · 9:16
Threads500Shows in full1080 × 1080 · 1:1
Bluesky300Shows in full1200 × 675 · 16:9
Pinterest500Shows in full1000 × 1500 · 2:3

Caption limits are character counts. “Cuts off at” is where the platform hides the rest behind a more link. Stories render no feed caption at all, so any text belongs on the image.

On images per post, the hard caps worth knowing are X (Twitter) allows 4, Threads allows 10, Bluesky allows 4. The rest are more generous than a single post usually needs.

Where captions get cut off

The limit is rarely the number that matters. What matters is how much of your caption a reader sees before deciding whether to expand it, and that number is much smaller:

  • Facebookabout 477 characters, then "See more"
  • LinkedInabout 210 characters, then "…more"
  • LinkedIn Carouselabout 210 characters, then "…more"
  • Instagramabout 125 characters, then "more"

Everything else in the list shows the caption in full, so the only ceiling is the character limit itself. The practical rule: write the first line as though it is the only line, because on the platforms above it often is.

Image sizes and aspect ratios

Upload one image and every platform crops it differently. These are the ratios each format supports, with the first being the default:

X (Twitter)

16:9 (1600 × 900), Square (1080 × 1080)

LinkedIn

Landscape (1200 × 627), Square (1080 × 1080), Portrait (1080 × 1350)

LinkedIn Carousel

Square (1080 × 1080), Portrait (1080 × 1350), Landscape (1200 × 627)

Instagram

Portrait (1080 × 1440), Square (1080 × 1080), Landscape (1080 × 566)

Facebook

Landscape (1200 × 630), Square (1200 × 1200), Portrait (1080 × 1350)

Threads

Square (1080 × 1080), Portrait (1080 × 1350), Landscape (1200 × 630)

Bluesky

16:9 (1200 × 675), Square (1080 × 1080)

Pinterest

2:3 (1000 × 1500), Square (1000 × 1000)

Formats not listed here use a single fixed crop, shown in the table above.

Questions

What is the Instagram caption limit?
Instagram allows 2,200 characters, but only about 125 of them are visible in the feed before the caption collapses behind a "more" link. Put anything that matters before that point.
How many characters can you post on X?
A standard X account can post 280 characters, and the whole post is shown rather than being cut off. Premium accounts can post considerably more.
Where does LinkedIn cut off a post?
LinkedIn accepts 3,000 characters and shows roughly the first 210 before a "see more" link, which is about three lines on desktop.
Do Stories have a caption limit?
Stories on Instagram and Facebook do not render a feed caption at all. Any text lives on the image itself, so the thing to check is the safe area rather than a character count.
Are these limits up to date?
These figures were last checked on 26 July 2026. They come from the same source that drives the PostDecks preview tool, so if a number here were wrong the previews would be visibly wrong too.

Rather than counting characters, see the cut-off drawn on the actual post.

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