Otter Blocks vs Stackable
Stackable is a careful, well built design toolkit. It is a layout and styling plugin first, and it stops there. Otter covers the same ground and then adds the things a site needs to actually collect leads: forms with stored submissions, mailing list integrations, popups and conditional content, all on the free plugin.
Free forever on WordPress.org. Otter Pro from $69 a year with a 30 day money back guarantee.
Free in Otter, absent or paid in Stackable
What is free in Otter, and what it costs in Stackable
Stackable is unusually generous with blocks: only two of them are Premium. The gap is not the block count, it is scope. Several things below are not gated in Stackable, they simply do not exist in it.
To be fair to Stackable, it does not claim to do forms or popups. If you are pairing it with a dedicated form plugin, the missing rows may not matter to you. If you were expecting one plugin to cover both, they matter a lot.
What you get without paying anything
Both lists below are the free download, with nothing bought.
Otter Blocks, free
Stackable, free
Where each feature actually lives
Read this as a map of scope and paywalls rather than a scoreboard. Rows where Stackable is ahead are marked too.
Four reasons to choose Otter Blocks
One plugin that captures leads
Otter has a form block that stores every submission in your WordPress database and lists it in wp-admin. Stackable has no form block at all, so a Stackable site needs a second plugin before it can take an enquiry.
Mailing list integrations, free
Connect a form to Mailchimp or Brevo on the free Otter plugin. Stackable has no form and no email service provider integrations, so this lives entirely outside it.
Popups without a second plugin
Otter ships a free Popup block. Stackable has a Video Popup lightbox and a dismissible notification block, but no popup or modal builder at any tier.
Conditional content and custom CSS, free
Otter gives you eight visibility conditions and custom CSS on every block in the free plugin. Stackable puts both behind Premium, and its conditions are the more detailed set once you pay.
What each side costs
Otter Pro
Priced on how many sites you run. Introductory pricing, renewals at full price.
Stackable Premium
Priced on site count, with an annual or a one off option.
How to read those numbers
Unlimited sites costs the same on both sides at $149 a year, and Stackable is cheaper at the single site entry point. Stackable also offers something Otter does not: a lifetime licence, and premium features that keep running once the licence lapses. The comparison that matters is what you still have to buy afterwards. A Stackable site that needs a contact form, a mailing list signup or a popup needs another plugin and another licence. With Otter those three are in the free download.
Moving from Stackable to Otter
You do not have to rebuild the site in a weekend. Both plugins can run at the same time while you move page by page.
Install Otter alongside Stackable
Otter registers its own blocks and leaves existing Stackable markup alone. Nothing on your live pages changes.
Add what Stackable does not cover
Before rebuilding anything, use Otter for the gaps: a form that stores submissions, a popup, a section with visibility rules.
Move the layout sections you want to consolidate
Rebuild Stackable containers, columns and cards with Otter blocks on the pages you touch anyway. There is no rush on pages that already look right.
Retire Stackable when nothing depends on it
Keep it installed while any page still uses its blocks. Once a page is fully on Otter, clearing out the leftovers removes a second set of assets from the front end.
When Stackable is the better pick
Three cases where we would point you at Stackable instead.
Common questions
Is Otter Blocks actually free?
Yes. Otter Blocks is on WordPress.org and the free plugin includes forms with stored submissions, Mailchimp and Brevo, eight visibility conditions, the Popup block, per block custom CSS and the AI tools. Otter Pro adds the WooCommerce builder, dynamic content, the autoresponder, file upload and Stripe form fields, CSV export of submissions, and over twenty visibility conditions in total.
Does Stackable really have no form block?
Correct. A form block appears on the Stackable roadmap but has not shipped, and it is not in the free or the Premium block list. Stackable sites use a separate form plugin. Otter includes a form block in the free download and stores every submission.
Can I run Otter and Stackable together?
Yes. They register separate blocks and do not conflict, which is the easiest way to migrate or to fill a gap. Two block libraries do load two sets of assets, so it is worth removing the one you stop using once a page no longer needs it.
Does Otter store form submissions without Pro?
Yes. Otter writes every valid submission to your WordPress database in both the free and Pro versions, and any administrator can read them under Otter Blocks in wp-admin. Exporting them as CSV or XML is the part that needs Otter Pro.
How do the visibility conditions compare?
Otter gives you eight in the free plugin, covering logged in state, user role, screen size, post author, post type, post category and post tag. Otter Pro takes that past twenty, adding post meta, user meta, query strings, country, cookies, date and time ranges, Stripe purchase history, seven WooCommerce rules and LearnDash course status. Stackable has none in the free plugin and eleven with Premium, including a custom PHP condition that Otter does not offer.
What happens to my site if I let Otter Pro lapse?
Your pages keep rendering. You stop receiving Pro updates and support until you renew. Otter Pro is introductory priced, so renewals are at the full list price shown on the pricing page.
How we checked this
Verified August 2026 against primary sources: the WordPress.org listings for otter-blocks and stackable; ThemeIsle documentation for the free versus Pro feature list, Form blocks, visibility conditions and marketing integrations; the Otter Pro pricing page; and Stackable documentation for conditional display and custom CSS, plus their pricing and free versus premium table, block list and roadmap. Capabilities and prices change often, so tell us if you spot something stale and we will correct it.
Try the free plugin before you compare licences
Install Otter Blocks, build one form, store one submission and add a popup. That is the whole argument, and it costs nothing to test.
Free forever on WordPress.org. Otter Pro from $69 a year with a 30 day money back guarantee.