# Social media post checker: check your post before you publish Paste your post, pick the networks and say what media you attach. The checker shows, per network, what would stop the post from publishing and what would make it look worse, using the same rules PostBoost checks before it sends a post. ## Why posts fail to publish Most failed posts break one simple rule: the caption is a few characters too long for X, an Instagram caption carries a sixth hashtag, or a post has more images than the network takes. Networks count differently too. X counts every link as 23 characters and an emoji as 2, Bluesky counts an emoji as 1, and Mastodon ignores the server part of a mention. The checker counts the way each network does, so a post that fits on LinkedIn but not on X shows up at once. ## Errors and warnings Red items block publishing: too long, too many hashtags, no media on a network that needs it (Instagram, TikTok, Pinterest and YouTube), too many files, a media type the network does not take, or a video that is too short or too long. Amber items publish but cost you reach or clicks: Instagram and LinkedIn hide the rest of the text behind see more, and Instagram captions do not make links clickable. ## Check once, post everywhere When every card says Ready, click Schedule this above to open the post as a draft in PostBoost and schedule it to all your networks at once. PostBoost runs the same checks again on the real accounts, including limits that depend on the account, before anything goes out. ## How to use 1. Paste or type your post. 2. Tick the networks you want to post to. 3. Enter how many images, videos or GIFs you attach, and the video length. 4. Fix everything marked in red: those posts would not publish. 5. Read the warnings in amber and decide if they matter for this post. ## FAQ ### How do I check a social media post before posting? Paste the post, tick each network and enter your media. Every network gets a card: Ready means the post passes PostBoost's publishing checks, Will not publish lists what to fix, and warnings point out things that publish but may hurt the post, such as a caption cut off by see more. ### What does the checker test? The length as each network counts it, the hashtag limit (PostBoost allows 5 per Instagram post), how many images, videos or GIFs a post may carry, video length limits on X, Threads, LinkedIn and Pinterest, the see-more cut-off on Instagram and LinkedIn, links that are not clickable in Instagram captions, and networks that will not publish a post without media: Instagram, TikTok, Pinterest and YouTube. ### Where do the rules come from? They are the checks PostBoost runs in its composer before it sends a post to a network. A test in our code fails whenever those rules change, so the checker and the app stay in step. Account settings such as X Premium or a Mastodon server's own limit are not known here, so the checker uses the defaults. ### Why is a TikTok photo post not checked? Whether TikTok accepts photo posts depends on a setting of the connected app, so the checker does not judge image posts for TikTok. Video posts are checked. ### What is the difference between an error and a warning? An error means the post would be rejected, for example a caption over the limit or too many images. A warning means the post goes out but may not look the way you want, for example a link that cannot be clicked or text hidden behind see more. ### Is my post sent anywhere? Not unless you click Schedule this. The checker runs in your browser. Schedule this sends the post to PostBoost to open it as a draft in your account. ## Related - [Social media character counter](https://postboost.co/tools/social-media-character-counter): Free character counter for X, Threads, Bluesky, Instagram, LinkedIn, TikTok and more. Counts as each network does, live in your browser. - [X thread maker: split long text into numbered posts](https://postboost.co/tools/x-thread-maker): Split long text into numbered posts for X, Threads, Bluesky or Mastodon. Never cuts a word or a link. Free, no signup, runs in your browser. - [Instagram hashtag generator](https://postboost.co/tools/instagram-hashtag-generator): Pick a niche and get a ready-to-copy set of Instagram hashtags, then add topic-specific suggestions. Free, no signup. - [Reliable publishing](https://postboost.co/features/reliability): PostBoost checks posts before they go out, warns you before an account disconnects and shows exactly why a post failed, so you can fix it and retry. - [How to Bold Text on LinkedIn (and When Not To)](https://postboost.co/learn/how-to-bold-text-on-linkedin): LinkedIn posts have no bold button. How to bold words in a post with Unicode letters, where real bold exists, and what styled text costs in reach and access. - [How to Schedule Posts on Bluesky (No App Password Needed)](https://postboost.co/learn/how-to-schedule-posts-on-bluesky): Bluesky has drafts but no scheduling. How to schedule Bluesky posts and threads with PostBoost, from the composer, the REST API or an AI assistant. - [Threads Character Limit 2026: 500 per Post, and Why Emoji Cost 4](https://postboost.co/learn/threads-character-limit): A Threads post holds 500 characters, but Meta counts each emoji as its UTF-8 bytes. All Threads limits: links, topic tags, media, alt text, attachments. Last verified: 2026-10-15 Canonical: https://postboost.co/tools/social-media-post-checker