Klaviyo vs Sleeknote.
Keep the email. Change the popups?

Klaviyo focuses its onsite editor on signup forms, including popup, flyout and embedded layouts. Mobile settings adapt the signup experience to smaller screens. Sleeknote separates desktop and mobile campaign designs and display settings. Teasers provide another entry point; on mobile, enabling a teaser replaces the usual opening triggers.

Klaviyo has more confirmed coverage of the shared signup-quality controls. Sleeknote’s outcome quizzes are a different reason to choose it: guided discovery and preferences that can then feed Klaviyo. Klaviyo collects email, phone, text, radio, dropdown and checkbox answers across multiple steps. Consent and hidden properties attach to the profile. Phone-format checks, CAPTCHA and double opt-in help protect the list; mobile tap-to-text provides another SMS signup route.

Sleeknote collects phone numbers, text, radios, dropdowns, answer buttons and consent checkboxes across multiple steps. Its paid Quiz format maps answer combinations to personalised outcomes and passes answer values to an email platform or CSV. Phone controls include format and accepted-country restrictions.

Klaviyo’s signup fields can collect preferences and customer information. Dedicated rating and quiz formats are assessed separately below. Sleeknote’s quizzes map combinations of answers to personalised outcomes and can send those answers to an email platform or CSV. Quizzes belong to the Gamification package; individual rating formats are checked separately.

Sleeknote offers the wider game toolkit and earns the higher score here. Klaviyo’s wheel may be enough for a straightforward signup promotion; Sleeknote’s extra package matters when the game itself is the campaign. Klaviyo offers a spin-to-win block with two to six slices. Each slice has a probability, success step and coupon. The signup can sit before or alongside the spin. This establishes a configurable wheel, not a library of scratch cards, calendars or outcome quizzes. Sleeknote’s Gamification package includes wheels, scratch cards, seasonal calendars, quizzes and Learn to Earn. Wheels support weighted prizes and losing outcomes. Calendar doors open on set dates; Learn to Earn combines lessons, questions and staged rewards.

The round is tied. Klaviyo uses form priorities and customer segments; Sleeknote has explicit campaign ordering and domain-level limits. Choose the workflow that matches how you organise offers. Klaviyo combines URL, UTM, device and location rules with lists and customer segments. Delay, scroll, exit and click triggers control the opening moment. Frequency settings limit repeat appearances, and form priorities decide which queued campaign appears first. Sleeknote combines URL, device, location, referral, UTM, cookie and new-visitor rules with time, scroll, exit, click and SiteData triggers. Per-campaign limits, a domain-level impression limit and Campaign order keep campaigns from competing.

Klaviyo supports more variations and a confirmed automatic-winner workflow. Sleeknote covers the practical two-campaign comparison; its read-only MCP can bring results into an assistant’s analysis. Klaviyo tests up to seven form variations, divides traffic evenly or by configured weights, and supports automatic winner selection. Results include revenue per variation. A test between form designs does not itself establish a no-form control group. Sleeknote Core includes split testing between two campaigns, with traffic allocation starting at 50/50. Saving the setup and activating the test are separate actions.

Klaviyo handles native broadcasts, segmentation and flows. Sleeknote plus Klaviyo can be a useful setup, but it involves two products and two budgets. A Klaviyo signup can enter a welcome flow from a list. Flows also respond to segments, events and dates, with delays and conditional paths for later messages. Broadcasts, segmentation, email and SMS belong to the same platform; profiles and sending allowances determine the bill. Sleeknote passes contacts and answers to an email platform. That platform sends the welcome sequence, runs later campaigns and charges for its own allowance. Native email sending is not confirmed in the shared evidence.

Sleeknote has a clear multi-domain offer. Klaviyo provides more detailed role and activity controls, but Portfolio should not be interpreted as an equivalent unlimited-domain popup subscription. Klaviyo provides predefined and custom roles, with separate responsibilities for content, analysis and account management. Owners and Admins can edit billing. An activity log records changes, and Portfolio groups accounts; that grouping is not a promise of one subscription for every website. Sleeknote Core includes unlimited domains and site profiles, with additional users and super users. Billing is restricted to the main owner. Capacity is shared according to the visitor-based subscription.

Klaviyo’s REST API can create, update and publish forms, with reporting endpoints for performance. Browser events connect forms to site code. Its MCP server exposes campaigns, flows, profiles and reporting with scope restrictions; flow webhooks send custom payloads to an endpoint. Sleeknote’s browser trigger opens an existing campaign, and Custom Integration sends submissions to an endpoint. Its read-only MCP connection exposes campaign and split-test data for external analysis.

Both meet the direct-support criterion. Sleeknote also lists phone support, while Klaviyo’s free email support has a 60-day limit. Klaviyo’s paid plans include email and live chat support, with availability depending on the plan and day. Free accounts receive email support for the first 60 days, then rely on self-service and AI-assisted help. Sleeknote lists phone, chat and email support in Core and Core + Gamification.

Klaviyo includes the form editor on Free. Draft, Live and Editing statuses separate work in progress from the form visitors see. Sleeknote lets you save campaigns separately from activation and edit desktop and mobile designs. Editor access starts with a 14-day trial rather than an ongoing free plan.

Both export data and measure campaign outcomes. Klaviyo also has confirmed scheduled reporting; Sleeknote’s read-only MCP is convenient for asking questions about onsite campaigns. Klaviyo reports submissions and revenue following form interactions, including revenue by test variation. Submitters can be grouped into a segment and exported. Custom reports can run on weekly or monthly schedules, and reporting APIs support external analysis. Sleeknote reports views, leads and conversion rates by device, source and location. Shopify adds purchase and revenue tracking. Leads and quiz answers can be downloaded, and MCP exposes campaign and split-test results.

Use Klaviyo alone when its forms meet the brief. Add Sleeknote when the onsite campaign needs its quiz, game or mobile controls, then map the answers into the profiles that your existing flows use. Klaviyo stores signups in its own profiles and sends its own email and SMS. Its marketplace connects stores, CRMs, review and loyalty systems, advertising tools and automation services. A flow can POST a webhook payload; that route is different from a dedicated form-submission webhook. Sleeknote connects to Klaviyo, other email providers, HubSpot, Salesforce, Google Analytics, Segment and Zapier. Its custom integration supports POST, JSON POST or GET and optional Basic Authentication. Quiz answers can carry destination field names and values.

Klaviyo’s documented customer, order and coupon operations give it the higher shared score. Sleeknote adds onsite recommendations and can pass the resulting subscriber data into Klaviyo rather than replacing it. Klaviyo connects Shopify customers, products, orders and events to profiles and flows. Forms can target cart conditions and customer segments, including tags and order history. Unique Shopify coupons support signup incentives and automatic application at checkout; product data also powers follow-up emails. Sleeknote’s Shopify app sends subscribers to Shopify and supplies purchase and revenue tracking. Shopify is also a product-recommendation connection. Coupon lists distribute codes, including rewards from game campaigns.

Klaviyo is cheaper in most shared scenarios, while Sleeknote supplies a confirmed multi-domain subscription. The table converts Sleeknote’s euro prices using the existing fixed ECB reference rate of €1 = $1.1225 dated October 19, 2026. It does not add an external email bill to a same-product quote.

Klaviyo charges for active profiles and email volume rather than pageviews. Free covers 250 profiles and 500 monthly emails. The first paid email tier costs $20 for up to 500 profiles and 5,000 emails; removing form branding requires paid access. SMS has separate pricing. Sleeknote Core costs €62 a month for up to 25,000 visitors and €74 for up to 50,000, with unlimited domains. Core + Gamification starts at €85 a month. A connected email provider is an additional cost.