Fairing vs KnoCommerce vs Zigpoll: Post-Purchase Survey Apps Compared

Open the Shopify App Store, search post-purchase surveys, and the same three names keep surfacing: Fairing, KnoCommerce and Zigpoll. All three sit at a near-perfect star rating. All three ask your customers how they heard about you the moment they check out. On the surface they look interchangeable.

They are not. The Fairing post-purchase surveys app, KnoCommerce and Zigpoll each charge you on a completely different basis, and that pricing model, not the feature checklist, is what decides which one is right for your store. Fairing charges by how many orders you do. KnoCommerce charges by how many features you switch on. Zigpoll charges by how many responses you collect. Pick the wrong model for your store and you either overpay or hit a wall.

Here is how they actually differ: real pricing, where each one is the better buy, and the one question none of them can answer no matter which you choose.

The 30-second answer

If you want the short version.

Zigpoll is the best all-rounder and the best value for most stores. One flexible app across post-purchase, on-site, email and SMS, AI analysis built in, and a free tier you can run a real programme on. Start here unless you have a specific reason not to.

Fairing is the attribution specialist. If your main job is working out which channels actually drive revenue, and you want that data wired deep into an analytics stack like Triple Whale, Fairing is the most focused tool of the three.

KnoCommerce is the research-depth option. If you have outgrown a single attribution question and want multi-question flows, benchmarking against other brands and in-survey upsells, Kno goes deepest, as long as you are ready for its $119-a-month Analyst plan, where the useful features actually start.

The rest of this piece is why.

Why this category exists at all

Post-purchase surveys got serious for one reason: your analytics stopped being able to tell you where customers come from. Since Apple’s App Tracking Transparency landed with iOS 14.5 in April 2021, a large share of iPhone users opt out of the tracking that ad platforms rely on. The pixel lost the plot, and self-reported attribution, asking the buyer directly on the thank-you page, became one of the few honest reads on channel performance left.

That is the job all three apps do. They catch the customer at the one moment they are paying full attention, right after checkout, and ask the questions your dashboards can no longer answer. If you want the deeper background on the attribution question itself, the how did you hear about us survey guide goes into the wording and the answer options; this piece is about which app to run it in. Where the three differ is how far past that single question they go, and what they charge you to get there.

Fairing: the attribution specialist

Fairing is the elder statesman of the group. It launched in 2018 as Enquire Labs, rebranded to Fairing, and is Shopify Plus Certified, which is why you see it on so many larger stores. At the time of writing it holds a 5.0 rating across more than 190 reviews on the Shopify App Store, and the reviews that stand out come from brands that have run it for three or four years without churning.

What Fairing does better than anyone is tie a survey answer to money. Every response is stitched onto the customer’s order and lifetime-value data, so you are not just seeing that 12% of buyers named TikTok, you are seeing what those TikTok-sourced customers are worth over time. It pushes that data into Klaviyo, Google Sheets, Elevar, Shopify Flow and analytics tools like Triple Whale, and it now ships weekly AI-generated attribution insights on top. If your survey data needs to live inside a wider measurement stack, this is the one built for it.

Fairing pricing

Fairing is the outlier on pricing: it charges purely by your monthly order volume, and every plan includes every feature. There is no gating. You get unlimited questions, LTV analysis, NPS, the integrations and the API on the free plan and the top plan alike. You simply pay for the size of your store.

• Free, up to 100 orders a month
• $15/month, up to 200 orders
• $49/month, up to 500 orders
• $149/month, up to 5,000 orders
• Higher volume tiers above that

All billed in USD, with a 14-day trial on the paid plans. The upside is obvious: a small store gets the full toolset free, and you never hit a feature paywall. The trade-off is just as clear. Your bill tracks your order count whether or not you send more surveys, so a high-volume store pays high-volume prices for what may still be a one-question survey. Fairing has also restructured its pricing since the Enquire days, so if you are on an older plan, work out your cost at your next order band before you assume it holds.

Fairing is the right pick if attribution is the whole job, you run enough volume to value the LTV tie-in, and you want the data feeding a proper analytics stack.

KnoCommerce: the research-depth option

KnoCommerce, branded KNO on the App Store, is the tool brands tend to graduate to when a single attribution question stops being enough. It launched in 2020, holds a 4.9 rating across a bit over 110 Shopify reviews, and its review page is full of brands that switched from Fairing wanting more depth: the ability to survey new and returning customers differently, to run multi-question logic flows, and to benchmark their answers against other Kno brands.

Depth is the whole pitch. Kno targets on more than 60 Shopify attributes, models your results as if 100% of customers had answered, and lets you fire in-survey actions, an upsell, an app-download prompt, a routed alert, so the survey earns its keep rather than just collecting data. It integrates with Klaviyo, Triple Whale, TikTok, Peel and, usefully for subscription brands, Recharge. Kno also reports average response rates north of 45% across its base, which is high for the category, though as with any vendor number, treat it as a best case rather than a promise.

KnoCommerce pricing

Kno charges by feature tier, and this is where you have to read the small print, because the headline “from $19” is doing a lot of work.

• Starter, $19/month: one survey, three questions, no integrations, no audiences
• Analyst, $119/month: two surveys, unlimited questions, 12 question types, four audiences, benchmarking, the order attribution report and two active integrations
• Pro, $299/month: four surveys, all question and action types, unlimited audiences, four integrations and a dedicated success manager in Slack

Billed in USD, with a 7-day trial and a discount for paying annually. The catch is that the $19 Starter plan is a demo in disguise: one survey, three questions, and crucially no integrations, so your data cannot flow into Klaviyo or your warehouse. The features that make Kno worth choosing, integrations, audiences, unlimited questions, benchmarking, only switch on at the $119 Analyst tier. NPS is an add-on with its own fee at every level, too. Budget for $119 a month, not $19, and Kno makes sense.

KnoCommerce is the right pick if you have a real research appetite, you want to segment and benchmark rather than just attribute, and you will use the Analyst feature set you are paying for.

Zigpoll: the flexible all-rounder

Zigpoll is the most-reviewed of the three by a distance, with a 5.0 rating across more than 500 Shopify reviews, and it is the one I would point most stores to first. Where Fairing specialises in attribution and Kno specialises in depth, Zigpoll’s edge is breadth: one app that runs post-purchase surveys, on-site polls, email and SMS surveys, and exit-intent and abandoned-checkout questions, all from the same place.

It is also the most modern on the features that matter day to day. Twenty-plus question types, automatic translation for multilingual stores, an AI survey generator, and AI analysis that themes and summarises your open-text answers so you are not reading 400 free-text replies by hand. The tracking script is deliberately light, under 20KB and loaded asynchronously, so it does not drag on your page speed. Integrations cover Klaviyo, Slack, Google Sheets, Looker Studio and 50-odd others.

Zigpoll pricing

Zigpoll charges by the number of responses you collect, and unlimited surveys come on every tier, including the free one.

• Lite, free: 100 responses a month, all question types, AI features included
• Standard, $29/month: 500 responses, automatic AI insights, SMS surveys, white-label
• Advanced, $97/month: 2,000 responses, API and MCP access
• Ultimate, $194/month: unlimited responses and a custom domain

Billed in USD, with 25% off for annual and no contract. This is the most forgiving model of the three for a store that surveys a sample rather than every single buyer. You can run a serious survey programme for $29 a month with AI analysis included, which is hard to argue with on value. The thing to watch is that responses, emails and SMS are all metered separately, so a high-volume store that wants to survey everyone will climb the tiers or need the unlimited plan.

Zigpoll is the right pick for most stores, and especially for anyone who wants one flexible tool across the whole site rather than a dedicated attribution appliance, at the lowest sensible entry price.

You are really choosing between three pricing philosophies

Strip away the feature lists and the decision gets simpler. These three apps have each answered the question “what should we charge for?” differently, and matching that answer to your store is most of the choice.

Fairing charges for your size. The more orders you process, the more you pay, and everyone gets every feature. It suits stores where attribution is worth real money and the order count justifies it.

KnoCommerce charges for capability. You pay to add depth, and a small store stays cheap only by staying shallow. It suits stores that will actually use the advanced tier.

Zigpoll charges for usage. You pay for how much you collect, and the features come along for the ride. It suits stores that want flexibility and a low floor.

There is no universally right answer, only the right answer for your order volume, your research appetite and how much of your buyer base you actually want to survey.

A practical way in: two of the three let you start for nothing, so start there and learn where you hit the wall. Fairing is free to 100 orders a month, Zigpoll to 100 responses, and Kno has no free tier at all, only a 7-day trial. Each wall sits in a different place. Fairing’s arrives as your order count climbs, Zigpoll’s when you try to survey more of your buyers, and Kno’s the moment you want an integration, because that needs the $119 plan. Work out which wall you will hit first and you know which bill you are really signing up for.

The comparison at a glance

Ratings and pricing move, so confirm the current numbers on each app’s Shopify App Store listing before you commit.

The fourth name you will see: Grapevine

One more app comes up constantly in this category, so it is worth naming. Grapevine carries Shopify’s Built for Shopify badge, holds a 5.0 across nearly 200 reviews, and leans on flat-rate pricing with unlimited responses. That flat rate makes it the value pick specifically for high-volume stores that would pay a fortune on Fairing’s order-based tiers or Zigpoll’s response-based ones. If your store does big numbers and you want to survey all of it, price Grapevine alongside the three above before you decide. For the wider field beyond these four, the best Shopify survey apps roundup sorts the whole category by the job you need done.

A word on the response rates vendors quote

Every app in this space will show you a big response-rate number. Kno cites 45% and up. Take all of them as best cases. The independent benchmark worth trusting is Survicate’s 2025 analysis of 4,332 surveys across 460 companies, which put the median response rate for on-site and in-app surveys at just under 10%, with the best short surveys pushing into the mid-teens and low twenties. A well-placed, two-question post-purchase survey on the thank-you page will sit at the top of that range. A seven-question one will not. The app matters less than the length and the placement, so whichever you choose, keep it to two or three questions and put it where attention is highest.

The one question none of them can answer

Every one of these apps shares one limit, and it is worth being clear-eyed about before you pay for any of them. A post-purchase survey can only ask people who have already bought. By definition, it is a read on the past. That is exactly what you want when the question is which channel is working or how the checkout felt. It is no help at all when the question is whether something will sell in the first place.

If you are weighing up a new product, a new pack size, a price change, a claim on the label or an ad you have not run yet, there is nobody to survey. The buyers do not exist. Surveying your existing customers about it just polls the people who already say yes to you, which is the most flattering and least useful audience for a decision about the unknown. It is a voice-of-customer blind spot, and it sits before the sale, not after it.

That forward-looking job is a different one, and it is the one place our own tool fits, so I will name it plainly rather than dress it up. With TestFeed you can test the idea itself, a product, a pack, an in-context price, an ad or a claim, in front of simulated shoppers before you commit stock or budget, and get back a purchase-intent read, their reasons in their own words, and a clear next move, in days rather than weeks. It is a pre-spend, directional signal, not a sales forecast, and it does not judge taste, texture or smell. Use it to decide what is worth launching. Then point one of the survey apps above at the customers it brings you. One tool looks forward before you spend; the other looks back once you have. If you only ever measure after the money is gone, you are optimising a decision you already made.

Frequently asked questions

Which is the best post-purchase survey app for Shopify?

For most stores, Zigpoll, because it is flexible across post-purchase, on-site, email and SMS, includes AI analysis, and has a usable free tier. Choose Fairing instead if attribution wired into an analytics stack is your priority, or KnoCommerce if you want multi-question research depth and will use its $119 Analyst plan.

How much do Fairing, KnoCommerce and Zigpoll cost?

All three bill in USD. Fairing is free up to 100 orders a month, then $15, $49 and $149 as your order volume grows. KnoCommerce is $19, $119 and $299 by feature tier, though the useful features start at the $119 Analyst plan. Zigpoll is free up to 100 responses, then $29, $97 and $194 by response volume. Confirm current pricing on each app’s listing, as it changes.

Is KnoCommerce or Fairing better for attribution?

Both are strong. Fairing is the more focused attribution tool, tying every response to order and lifetime-value data and feeding stacks like Triple Whale, and it includes all features on every plan. KnoCommerce goes deeper on multi-question flows, benchmarking and new-versus-returning logic, but you need its $119 Analyst tier to switch on integrations. Pick Fairing for focused attribution, Kno for research depth.

Do post-purchase surveys slow down my store?

A well-built one should not. Thank-you and order-status page surveys load after the purchase is complete, so they do not touch checkout speed, and apps like Zigpoll use a lightweight asynchronous script specifically to protect page-speed scores. Keep the survey to two or three questions and it stays invisible to the customer’s experience.

How to choose this week

Name the job first. If you need to know which channels drive revenue and you want that data in your analytics stack, trial Fairing. If you want to go deeper than attribution into real customer research, trial KnoCommerce at the Analyst tier, not Starter. If you want one flexible, good-value tool for surveys across your whole store, start with Zigpoll’s free plan and upgrade when you outgrow it. All three are good, which is why they all sit near five stars. The winner is the one whose pricing model matches how your store actually works. One last thing to ask before you commit, because none of the vendors will raise it: what leaves with you if you switch later. Your survey history mostly lives inside the tool you picked, so a store planning to run this for years should check how cleanly each one lets you export before betting several years of attribution data on it.

Then remember what the survey cannot do. Once you have picked your app and pointed it at your customers, you are measuring decisions you have already made. The bigger wins come from getting the decision right before you spend, which means testing the product, price or ad while you can still change it. Measure after. Test before. Do both and you stop guessing at either end.