Ranking updated on July 20, 2026.
Are you looking for the best Klaviyo agency to structure your email marketing? Our 2026 verdict can be summed up in one sentence: the French market has a handful of truly specialized agencies, each with a preferred area, from pure retention to the Shopify + Klaviyo duo. Stellar Projects comes out on top of our ranking, an auto-inclusion that we explain just below. This email marketing agency comparison scrutinizes them with a transparent methodology and verifiable facts for each.
Transparency: This comparison includes Stellar Projects, our own structure. We chose assumed self-inclusion rather than a false neutral ranking: our figures are verifiable (25 to 30% email revenue on average for our managed accounts, published pricing grid) and we list our competitors by name, with their strengths. It's up to you to judge.
Summary
Our selection methodology
Who evaluated: the Stellar Projects team, a Klaviyo and Shopify Plus Partner agency, which also operates its own brands (Cabania). This ranking reflects our reading of the market in July 2026: it is editorial, reasoned, and assumed. Each structure was evaluated on five criteria:
- Real Klaviyo specialization: share of activity dedicated to email marketing and CRM, depth of use cases (flows, segmentation, deliverability).
- Klaviyo Partner status and certifications: as publicly displayed by each agency, without extrapolation.
- Verifiable evidence: named clients, quantifiable cases, nominative testimonials available online.
- Pricing transparency: published grid or communicated ranges before the first meeting.
- E-commerce integration: ability to treat the store and email as a single system, particularly on Shopify.
The 2026 ranking at a glance
| Rank | Agency | Stated positioning | Verifiable fact | Pricing |
|---|---|---|---|---|
| 1 | Stellar Projects | Klaviyo and Shopify Plus agency, email + store as a single system | 25-30% email revenue on average for managed accounts, published pricing grid | Setup €2,000-€5,000, then €1,000-€3,000/month |
| 2 | ThirtyFive | CRM, email marketing, and e-commerce retention agency | 100% CRM, email marketing, and e-commerce retention positioning displayed on its website | By quote |
| 3 | Standard Ecom | Klaviyo agency, CRM and email marketing experts | Publicly lists Jimmy Fairly, Nutripure, and The Bradery among its clients | By quote |
| 4 | Emailio | Klaviyo agency, email and SMS retention for e-commerce | Offers a free audit displayed on its website | By quote |
| 5 | W3Lead | Parisian Shopify Plus agency with a CRM division | Parisian Shopify Plus agency with a displayed CRM division | By quote |
The top 5 Klaviyo agencies in France
1. Stellar Projects, email and the store as a single system
Our conviction, and the reason for our place in this ranking: email marketing only performs if the store, tracking, and flows are designed together. As both a Klaviyo and Shopify Plus Partner agency, we observe 25 to 30% of revenue attributable to email on average in the accounts we manage, we publish our pricing grid, and we test our methods on our own Cabania brand. Details of the offer are on our Klaviyo agency page.
“Thanks to their Shopify + Klaviyo expertise and their 360° support, we were able to make the switch in record time and saw improved performance at all levels!”
Amandine Danulot, E-commerce Manager
2. ThirtyFive, retention as its sole business
ThirtyFive presents itself as a CRM, email marketing, and e-commerce retention agency: a total specialization in the subject, which makes it a benchmark in the French market for brands whose main challenge is customer loyalty. The right choice if you are looking for a single-subject partner with deep industry expertise.
3. Standard Ecom, mainstream references
Standard Ecom boasts leading French DTC references, including Jimmy Fairly, Nutripure, and The Bradery, publicly cited on its website. A reassuring choice for established brands that want a partner accustomed to high sending volumes.
4. Emailio, the email and SMS duo
Emailio positions itself on e-commerce retention via Klaviyo, with a combined email and SMS approach and a free audit offered as an initial engagement. Relevant for brands that want to activate the SMS channel in parallel with email.
5. W3Lead, the CRM division of a Shopify Plus agency
W3Lead is primarily a Parisian Shopify Plus agency, with a CRM and email marketing division: a configuration similar to ours, relevant for brands that want a single technical contact for both the store and email.
Honorable mention to generalist agencies with a Klaviyo division (Dedi Agency in Lyon, in particular): solid in execution, they are suitable for brands that already have a clear CRM strategy.
How to compare Klaviyo agencies?
Beyond any ranking, including ours, here is the comparison framework we recommend applying to each candidate:
- Ask for the observed email revenue share for their client accounts: a serious agency has this figure, and it should be around 25 to 30% for mature accounts.
- Check for evidence, not promises: named clients, signed testimonials, before/after cases. Anonymous stars don't count.
- Demand pricing transparency before the first meeting: setup, monthly, scope. A vague pricing structure indicates potential cost overruns.
- Test dual competency: who configures the Shopify tracking on which all flows depend? If the answer is "your developer," the agency only covers half the topic.
- Clarify ownership: Klaviyo account, templates, and data must remain yours, contractually.
How much do these agencies cost?
Most agencies on the market work on a quote basis. To give you an idea, we publish our own pricing: €2,000 to €5,000 for the initial setup (audit, integration, fundamental flows), then €1,000 to €3,000 per month for ongoing support, excluding the platform subscription whose tiers are detailed in how much Klaviyo costs. These ranges provide a good benchmark for evaluating the quotes you receive.
And if you're new to the ecosystem, start with our ultimate guide to Klaviyo or compare the tool to its alternatives with Brevo vs Klaviyo.