Note: Competitor pricing and plan details below were checked against each vendor’s own site on 29 August 2026. Prices change often, so verify before committing.
A unified posting API replaces one OAuth flow, one media pipeline and one rate limit per platform with a single integration. The five below all do that. They differ enormously on price of entry and on whether you can run them yourself.
At a glance
| API | Entry price | Self-host | API on free tier |
|---|---|---|---|
| BulkPublish | $13.99/mo | No | Yes, 30 requests/day |
| Postiz | $29/mo cloud, free self-hosted | Yes | Self-hosted only |
| Buffer | $5/channel/mo | No | Yes, 3,000 requests/month |
| Mixpost | $299 one-time (Pro) | Yes | Pro and above |
| Ayrshare | $149/mo | No | 28-day trial |
1. BulkPublish
- Entry: Pro is $13.99/mo ($11.89 yearly), Business is $39.99/mo ($33.99 yearly)
- Surface: 59 documented endpoints covering posts, scheduling, media, channels, labels, analytics, RSS feeds and quotas
- Auth: API key, or OAuth 2.1 with granular scopes for acting on other people’s accounts
- Platforms: 15
Rate limits by plan:
| Free | Pro | Business | |
|---|---|---|---|
| API requests/day | 30 | 5,000 | 50,000 |
| API keys | 1 | 5 | 10 |
| The API is available on every plan including free, which is unusual: 30 | |||
| requests a day is enough to build and test an integration end to end before | |||
| paying. Character limits and per-platform media rules are validated when the | |||
| post is created rather than at publish time, so a bad payload fails where your | |||
| code can catch it. |
2. Ayrshare
- Entry: Premium $149/month for 1 profile and up to 14 accounts
- Launch $299/month for up to 10 profiles, Business $599/month for 30
- Trial: 28 days, no card required
- Platforms: 14+
The most API-first product here, and priced for businesses embedding social posting into their own product rather than for individual developers. Pricing is per profile, where one end customer with six connected networks counts as a single profile, which is the right shape if you are reselling to customers.
Volume pricing falls from $8.99 to $1.99 per profile at scale. The $149 entry is the highest on this list by a wide margin.
3. Postiz
- Entry: $29/month cloud for 5 channels, up to $99/month for 100
- Self-hosted: free and open source
- API: REST plus webhooks, included on paid cloud plans
The best option if you want the choice between paying and hosting. Self-hosted costs nothing but your own infrastructure; the cloud tiers are priced by channel count rather than by request volume.
If you are going to self-host anyway, the API comes with it at no licence cost.
4. Mixpost
- Lite: free, open source, self-hosted, and publishes to Facebook Pages, Mastodon and X only
- Pro: $299 one-time, unlocks all platforms and API access
- Enterprise: $1,199 one-time, adds white-label and customer management
The only one-time payment on this list. Against a $29/month cloud plan, $299 pays for itself in about ten months, and the licence is perpetual.
The cost is operational rather than financial: server, updates, backups and platform-approval work are yours. Note that API access is a Pro feature, so the free Lite tier is not an API option.
5. Buffer
- Entry: $5/channel/month billed annually
- Free tier API: 1 key, 3,000 requests/month
- Paid API: 3 keys, 7,500 requests/month on Essentials
Worth listing because the free tier includes real API access, which most consumer schedulers do not. The allowance is monthly rather than daily, so 3,000 a month is roughly 100 a day.
The constraint is that Buffer is a scheduling product with an API rather than an API product, and its per-channel pricing scales with connected accounts.
Test before you commit
An afternoon tells you more than any comparison, this one included:
- Connect one account per platform you care about. Some are harder than the docs suggest.
- Publish a real post to each and check it arrived looking right, not just that you got a 200.
- Deliberately break one. Send a caption over a platform’s limit and see when and how you are told. Validation on create versus at publish time is the biggest practical difference between these products.
- Publish media, especially video, where the differences are largest.
- Revoke a connection on the platform side and see whether the API tells you clearly.
Steps three and five are what separate them. Anything can post text on a good day.
The short version
For an integration where publishing is a feature of your product, BulkPublish is the cheapest way in and the only one with a usable API on a free tier. Ayrshare is built for reselling to end customers and priced accordingly. Postiz and Mixpost are the ones to look at if you would rather host it, with Postiz free to self-host and Mixpost a one-time licence. Buffer is a scheduler with an API attached rather than an API product.