Free tools
PostLake keeps a registry of what each social network will and will not accept, because its API has to refuse a bad post before it costs anyone money. These tools are that registry, opened up. No account, no upload, no catch.
Nothing leaves your browser. Every check runs locally.Paste a caption, attach your media, and get every network's verdict at once: what publishes, what gets refused, and the exact change that fixes it.
Check a postOne caption counted against nine limits live, including X's odd arithmetic where every link is 23 characters and most emoji count double.
Count a captionDrop an image and see who takes it on pixels, weight and format. Where one refuses it, make a version it accepts in a click.
Check an imageThe whole registry in one table, so the answer to "can I even do this there" does not need a tool at all.
Scroll the table sideways to see every column.
Most tools like these are a list somebody typed out once and never updated. These read capabilities.json, which is generated from the registry PostLake's publish path validates against. When a network moves a limit, the API changes and these pages change with it. There is no second copy to go stale.
PostLake is the social media API for AI agents. One integration publishes, schedules and measures across every major network, with idempotency keys, safe retries and one normalised response an agent can reason over. Free to start, no card.
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