These are not one API with three logos. Each platform gates publishing on something different — Instagram on the account type, LinkedIn on whether you are a registered company, TikTok on an audit of your app — and the gate that stops you depends less on what you are posting than on whose account you are posting to.
What follows is the reference we wanted while building NOISEY and could not find: what each one actually permits, what it costs in calendar time, and where the API is the right answer and you need neither a phone nor a desktop app.
Instagram: professional accounts, and one of two doors
Publishing through Instagram needs a professional account — Business or Creator. A personal account cannot publish through the API, there is no application form that changes that, and Meta has never offered one. If your client will not convert their account, the API route is closed before it starts.
Once the account is professional there are two products, and people routinely pick the harder one by accident. Instagram API with Facebook Login requires the professional account to be linked to a Facebook Page. Instagram API with Instagram Login requires only the professional account itself — no Page, no Business Manager gymnastics. If nobody involved wants a Facebook Page, use the second.
The ceiling is 100 API-published posts in a rolling 24 hours, with a carousel counting as one post. Worth knowing before you plan around it: Meta's own field reference for content_publishing_limit still says 50, a leftover from the previous value. Query the endpoint for the account and trust the live number over either page.
The part that costs weeks is not the code. Publishing for anyone who is not a developer or tester on your own app needs App Review plus business verification. Posting to your own account is an afternoon; posting to a client's is a review cycle.
LinkedIn: your own profile is easy, a company page is a different company
Posting to your own profile is the friendliest thing in this whole post. Create an app, request Share on LinkedIn, ask for the w_member_social scope, and the member who signs in can publish immediately. Same day, no partner programme, no forms.
Posting to a company page is a different product with a different eligibility test. The Community Management API is available to registered legal organisations only — not to individuals, not to solo developers, not to an unregistered side project. You supply a business email, the legal name, the registered address, a website and a privacy policy; a super admin of the LinkedIn Page tied to your organisation verifies the application; and access comes in two tiers, Development first against test pages, then Standard for real ones, with a screencast demonstrating each use case you asked for. Every step is a human reading your submission.
There is also no published rate limit to plan against. “Standard rate limits are not published in documentation” — you look yours up in the Developer Portal, on the Analytics tab, which only shows endpoints you have already called at least once today. So the way to discover your ceiling is to make a call and then go and read it.
And three things stay locked at every tier, as of August 2026: PDF document carousels, long-form Articles, and native reposts. No third-party tool publishes those, because the restriction is in the API rather than in the tools.
TikTok: the audit, and a quota that is not yours
TikTok's Content Posting API will let an unaudited client post on day one, which is exactly the trap. “Unaudited API Clients can only post contents in SELF_ONLY viewership” — the upload succeeds, the response is a 200, and the video is visible to the creator and nobody else. Public posting needs an audit of your client against TikTok's terms.
Past the audit there is a second surprise. There is a cap on posts to a creator account per 24 hours through Direct Post — commonly around 15 — and TikTok says it plainly: “shared across all API Clients using Direct Post”. The quota belongs to the creator, not to your integration, so another scheduler your client signed up for spends your budget. Video initialisation is separately capped at 6 requests per minute per user access token.
The full version of that story, including why a scheduler can be rejected for the shape of its own interface, is in why your scheduling tool can't post to TikTok the way you expect.
Three ways to be told no, and only two of them say so
The failure shapes matter more than the eligibility rules, because two of these tell you at the door and one tells you by publishing something invisible.
The pattern: these APIs were built for a brand, not an agency
Line the gates up and they are the same shape. One legal entity, one professional account, one reviewed app, one token. That is a brand publishing its own content, and for a brand publishing its own content every one of these APIs is good.
An agency is not that. It is one company holding relationships with many separate account holders, each of whom owns their own account and signs in themselves. Every gate above is answered per account holder — so the work does not scale with your engineering, it scales with how many clients will convert an account, appoint you a page admin, or sit through a review.
Where the API is the right answer
One brand, one professional account, volume that fits inside the ceiling: use the API. It is more reliable than any UI automation, and it is not close. There is no screen to change under you, no phone to unplug, no app update to break a selector. Errors come back structured and documented. Nothing in this post is an argument against that, and if you fit it you should stop reading here.
The same is true of the easy half of LinkedIn. If the job is “post to my own profile on a schedule”, that is an afternoon's work with w_member_social and it will outlive anything with a phone in it.
Where it is not
- Personal Instagram accounts — no route, at any price.
- Clients who will not convert to a professional account.
- A company page where nobody will make you a super admin, or where your own side project is not a registered organisation.
- Content types the API refuses — LinkedIn carousels, Articles, native reposts.
- Volume that a shared quota will not take, on TikTok in particular, because you cannot see what else is spending it.
The other route, with its costs said out loud
The alternative is not clever: the real app, on a phone you own, signed in as the account holder, driven over a cable from your own machine. There is no API client involved, so none of the gates above apply — and the constraint becomes the account's own ordinary limits, the same ones a person tapping the screen would hit.
What that costs, stated rather than glossed:
- Hardware. A handset per account, plugged in, powered, on your desk.
- A real login, done by hand. Someone accepts the terms and signs in on the device. NOISEY deliberately stops at a consent gate and asks for a human rather than tapping Agree and continue on someone's behalf — accepting terms for another person is not a thing software should do quietly.
- Maintenance. Apps move their buttons. UI automation is a thing you keep, not a thing you finish.
- Supervision. Something will fail on a Tuesday, and the honest design goal is that it fails loudly rather than never.
Where NOISEY sits, precisely
NOISEY is not an API reseller and does not proxy anything. There is no access token for Instagram, LinkedIn or TikTok anywhere in our database — a client profile stores a platform, a handle and a link you can click, and that is the whole of it. Posting happens on the handset in front of you; our servers store media and decide when, and cannot drive a phone even if someone took them.
The vocabulary, since it matters for reading the rest of the docs: a routine is what a phone does, an automation decides when it runs, and both are described in what the desktop app and the website each do. You are responsible for what gets posted from your accounts — stated in the docs in those words.
Three things NOISEY does not do, because they come up whenever devices are mentioned: no device fingerprint changing, no proxy rotation to make one operator look like many unrelated people, and no bulk account registration. The premise is the opposite of that — your devices, your accounts, your connectivity, one real account holder per account. If that is not the shape of your problem, the tools that promise otherwise are not the ones we compete with.
For the case where a client is a real person with a real account and the API simply will not let you in, the argument is worked through in one phone per client, and the mechanics of the boring version — a folder that becomes a post — are in from a folder to a posted video.