Side by side

poster vs sydium

Plans read from both vendors' own pricing pages, with the same seats and billing applied to each. sydium is a verified alternative to poster: it does the same main job for a similar customer.

poster

Posterly is a social media management platform that enables users to create, schedule, and publish posts across 18 platforms using AI integration. It supports solo creators, small teams, agencies, and businesses with features like AI-powered captions, video generation, client approval workflows, and analytics.

Starting price: From $5.58/mo
Price clarity: Price clarity grade C, 67 out of 100 67 of 100
Category: Marketing & advertising
Platforms: Not confirmed
Good fit for: Solo creators, small teams, agencies, and businesses needing multi-platform social media management with AI support
Limitations: Some story elements like link stickers and polls require manual reminders as social APIs cannot publish them directly

sydium

Sydium is an AI-powered social media management platform that learns your writing style to draft, schedule, and publish posts across eleven platforms. It offers voice training, autopilot posting modes, unified inbox for engagement, and analytics with a public API for integration.

Starting price: Price not published
Price clarity: Not graded
Category: Marketing & advertising
Platforms: Not confirmed
Good fit for: Users who want automated social media posting with voice consistency and minimal manual effort.
Limitations: Does not run paid ads or handle influencer outreach; manual graphic design is limited to AI image generation.. X/Twitter posting is capped at 10 posts per month due to API limits.

What each one costs your team

THE COST FOR YOUR TEAM

Go beyond the starting price.

Published plan prices for your team size and usage. Results update as you type. Taxes, currency conversion and unlisted add-ons are excluded, and anything the source did not state is called out rather than guessed.

PeopleBillingCurrencyPrices are shown as published. No exchange rates are applied.Monthly usage per toolApplies to each tool’s own unit. Leave at 0 for subscription cost only.

Known monthly subtotal

$5.58/month

1 of 2 tools could not be priced with these inputs, so this is not the full cost.

Some figures carry conditions the vendor did not state — see the notes beside each plan.

Plan costs based on your requirements
Tool / plan	Monthly	Per year	What this assumes
poster StarterCheapest fit Flat subscription	$5.58	$67.00	· Only annual billing is published; shown as the monthly equivalent of the annual price. Paying month to month may cost more. Automatically extracted from the linked pricing source. Seat allowances, usage limits, taxes and terms are not confirmed — check them with the provider.
poster Pro Flat subscription	$12.00	$144.00	· Only annual billing is published; shown as the monthly equivalent of the annual price. Paying month to month may cost more. Automatically extracted from the linked pricing source. Seat allowances, usage limits, taxes and terms are not confirmed — check them with the provider.
poster Power Flat subscription	$20.00	$240.00	· Only annual billing is published; shown as the monthly equivalent of the annual price. Paying month to month may cost more. Automatically extracted from the linked pricing source. Seat allowances, usage limits, taxes and terms are not confirmed — check them with the provider.
poster Agency Flat subscription	$39.17	$470.00	· Only annual billing is published; shown as the monthly equivalent of the annual price. Paying month to month may cost more. Automatically extracted from the linked pricing source. Seat allowances, usage limits, taxes and terms are not confirmed — check them with the provider.
sydium	No pricing recorded yet. Check the official site, or ask the owner to add it.

poster

Best fit

Solo creators, small teams, agencies, and businesses needing multi-platform social media management with AI support

Trade-offs

Some story elements like link stickers and polls require manual reminders as social APIs cannot publish them directly

Integrations / export

Integrates with AI providers like ChatGPT, Claude, Gemini, Cursor, and others via MCP, Supports media uploads from Google Drive, Canva, and local files, Analytics reports can be exported as PDFs and spreadsheets

sydium

Best fit

Users who want automated social media posting with voice consistency and minimal manual effort.

Trade-offs

Does not run paid ads or handle influencer outreach; manual graphic design is limited to AI image generation.; X/Twitter posting is capped at 10 posts per month due to API limits.

Integrations / export

Brand Voice training uses posts from Instagram, TikTok, YouTube, Facebook, X, LinkedIn, and Threads as sources.

List name

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