Companies Using Seznam Sklik

Seznam Sklik is the second-largest tool in our Retargeting & Remarketing category, and it isn't a retargeting tool. Sklik is the self-serve ad system of Seznam.cz, the Czech search engine and portal, and what our October 2026 crawl counts is its measuring script: rc.js, served from c.seznam.cz. Sklik's help pages give the same file for its older retargeting code and conversion code, which Seznam's new SEM script, sul.js from l.seznam.cz, has replaced for new setups since June 2026. The conversion code can also measure Zboží.cz, Seznam's shopping search. That gives 14,269 domains, 5,943 of them matched to a company, 2nd in the category with 13.55%.

What the count measures

A domain counts when a page on it loads a script from c.seznam.cz. Wherever our crawl recorded the address of that script, on 4,858 domains, it was a Sklik file: /js/rc.js on 4,840 and the older /js/retargeting.js on 15, with 3 recorded without a path. Other Seznam hosts turn up on the same sites, such as h.seznam.cz on 2,529 and the publisher ad script ssp.seznam.cz on 77, but the rule doesn't count them. Two limits follow. A company that buys only Sklik search ads and never adds the code is invisible to us, so the figure is a floor on Sklik advertisers. And a site that kept the code after it stopped buying ads still counts: Sklik's hit server returned the same 43-byte image for every account ID I sent it, made-up ones included, so a paying account and a lapsed one look the same from outside.

Sales signal: read this list as sites that measure for Seznam, a narrower group than Seznam advertisers and a more useful one. These owners did the tagging work, so they're the ones reporting on Sklik conversions.

Whose account is it?

Platforms and agencies sometimes run a vendor's tag under their own account, which inflates a count, so I read the account IDs. In the raw HTML of 400 random Sklik domains, 141 exposed a retargeting or conversion ID. We read 145 different IDs, and none appeared on two domains. The biggest platform is Shoptet: 111 of the 400 were Shoptet stores, and 79 of them carried rc.js with an ID that Shoptet writes into the page from the merchant's own settings. Sklik's help names Shoptet among the platforms with their own Sklik setup. Webnode, the Czech website builder, does run Sklik under its own account (ID 10820, in its tag manager), but only on Webnode's own hosts: 45 Webnode domains and 39 login addresses for customers' projects, 84 in all and 0.59% of the count. Customer sites built on Webnode carry Webnode's platform container, and that container has no Sklik tag.

Sales signal: one ID, one site. A Sklik list here is close to a list of individual advertisers, with no agency fleets to dedupe first.

Growth: read the step carefully

The chart reads 10,760 domains on 1 August, 13,921 on 1 September and 14,269 on 1 October 2026. Don't read the August step as a rush of advertisers. The set of domains we crawl turns over every month, with dead sites dropping out and new ones added, and our detection of Seznam's script widened over the same weeks. September to October added 348 domains. Since we began tracking drops on 4 August, 927 domains have lost the script on at least one hostname. 377 of those still run it on another, so about 550 no longer show rc.js on any hostname we crawl. Not all of them left Sklik: 78 of the domains that dropped the script now load Seznam's new SEM script instead, and 369 more load only the new script, so this count will undercount Sklik as advertisers move.

"In our 400-domain sample, each Sklik ID sat on exactly one domain, and the one platform account we found, Webnode's, covers only its own 84 hosts." - Sophie Clarke, Product Marketing Manager at TechnologyChecker.io

Sales signal: treat the pool as about 14,000 domains, set to shrink as advertisers move to Seznam's new SEM script, which this count doesn't include. Before treating one of the 550 or so leavers as lost to Sklik, check its pages for l.seznam.cz/sul.js.

Small Czech companies, with a careers-site tail

54.65% of matched companies with a known size have 1 to 10 employees and 27.11% have 11 to 50. By founding decade the 2010s lead (36.67%), then the 1990s (25.69%) and the 2000s (19.53%). Only 70 companies have more than 1,000 staff, and the big names often run Sklik on one site rather than the main one: ŠKODA on its careers site, Air Bank on its careers pages, MAKRO on its SmartChef recipe site, PayU on its Hungarian site. PwC Czech Republic, Elis, Plzeňský Prazdroj and Prusa Research run it on their main Czech sites.

Sales signal: the typical buyer is an owner-run Czech business with a web shop or a lead form. In large firms it's often HR or one product team, so recruitment-ad and HR-tech sellers should start with the careers-site group.

One country

Czechia accounts for 5,483 of the 5,943 matched companies, 92.26%. Slovakia has 68, Germany 63 and the United States 51; no other country reaches 13. Foreign-registered names include Elis, on its Czech site cz.elis.com, and Toyota Tsusho Europe. That matches what Seznam sells: Sklik's own site says it reaches over 97% of the Czech internet population, through Seznam.cz search, Zboží.cz and partner sites.

Sales signal: outreach needs Czech. A foreign company carrying Sklik's code is advertising to Czech searchers, which makes it a warm prospect for Czech-market agencies.

Shoptet and the rest of the stack

These shares are of Sklik's domains in our October 2026 crawl. Shoptet runs on 25.57%, then Upgates (4.32%), WooCommerce (3.41%) and PrestaShop (2.21%); WordPress is on 18.05%. Google Analytics is on 95.78%. DoubleClick Floodlight sits on 21.39% and Microsoft Advertising on 11.02%, so a fair share of these advertisers buy from Google and Microsoft as well. Local tools mark the market: Foxentry address checking on 6.6%, Biano's shopping pixel on 2.28%.

Sales signal: Shoptet's app store reaches a quarter of this list in one place.

Rivals, overlaps and the twin row

We have no switching data for Sklik, because no pair passes our tests. The tools in this category rarely sit beside it. 57 domains run Sklik and RTB House today, and 76 have had both at some point; 2 run Sklik and Albacross. Sklik's real rival is Google Ads, which sits in our Ad Networks category. One more thing: the category table also lists a row called Sklik. It counts the same Sklik code loaded from Seznam's older address, c.imedia.cz, which serves the same script file as rc.js, and 553 live domains appear under both. It isn't a competitor.

"Sklik's neighbours in this table are retargeting and identity tags. The tool Czech advertisers weigh it against is Google Ads, and that comparison lives in a different category." - Sophie Clarke, Product Marketing Manager at TechnologyChecker.io

Sales signal: for a Google partner, every Sklik site is a business already paying for Czech search ads. For a retargeting vendor, the 57 shared domains show how few Czech shops run a second retargeting buyer.

What it costs

Sklik's payments page (checked 15 October 2026) lists no entrance fee and no minimum spend. Advertisers top up a prepaid Seznam wallet and pay per click on search and display ads, or per thousand impressions on the display network only. The minimum bid is CZK 1 per click before VAT.

Sales signal: with no minimum spend, many of these accounts are small. Budget, not the tag, separates the serious advertisers from the rest, so qualify on company size and ad stack.

Key takeaways

1. 14,269 domains run Sklik's measuring script, 2nd in Retargeting & Remarketing with 13.55%.

2. The count is sites measuring for Sklik with the older rc.js code, a floor on its advertisers that will fall as sites move to SEM.

3. In a 400-domain sample, 145 IDs sat on 141 domains with none shared: no agency or platform fleets.

4. 92.26% of matched companies are Czech, and 54.65% have ten staff or fewer.

5. A quarter of the domains are Shoptet stores.

How to use this list

Filter by Shoptet for e-commerce pitches and by company size for B2B ones, then check which site carries the code at the 70 companies with more than 1,000 staff. The full list of 14,269 Seznam Sklik domains, with company, size and stack data, is on TechnologyChecker.io.