> ## Documentation Index > Fetch the complete documentation index at: https://help.chatarmin.com/llms.txt > Use this file to discover all available pages before exploring further. # Segmenting with Klaviyo Lists & Segments > Chatarmin guide: Segmenting with Klaviyo Lists & Segments # Segmentation with Klaviyo *** You can use the **Klaviyo information,** you have on your clients to create specific segments. These segments can later be used to do splits in Flows via **If/Else** splits or to **send campaigns to specific user cohorts**. This way you can create a List or Segment or use an existing one inside of Klaviyo with your existing data and **fetch the** [**Segment in Chatarmin**](https://chatarmin.com/dashboard/audience/segments). Chatarmin help center image ## How Klaviyo Sync Works *** When you select a Klaviyo List or Segment in Chatarmin, Chatarmin pulls the profiles from Klaviyo via the Klaviyo API. There is one important limitation to be aware of: > ⚠️ **Klaviyo allows a maximum of 100 profiles per API call.** This means that the larger your Klaviyo segment, the longer the sync will take inside Chatarmin. | Segment Size | Expected Behavior | | -------------------------------- | ------------------------------------- | | Small (\< 5,000 profiles) | Syncs quickly | | Medium (5,000–50,000 profiles) | Takes a few minutes | | Large (50,000–300,000+ profiles) | Can take a very long time or time out | If your segment appears to not load or shows no results, the most likely cause is that the segment is **too large to sync efficiently** via the Klaviyo API. *** ## Building a "WhatsApp Only" Segment — Best Practice *** A common use case is excluding contacts who are already on your email list, so that you only send WhatsApp campaigns to contacts who have opted in to WhatsApp exclusively. **❌ The approach that doesn't work well:** Trying to *exclude* a large Klaviyo email list (e.g. 300,000 email subscribers) directly inside Chatarmin. Due to the API limit above, this sync will take extremely long or fail silently. **✅ The recommended approach:** Since Chatarmin **automatically syncs WhatsApp opt-ins back to Klaviyo**, your WhatsApp subscriber data already lives in Klaviyo. This means you can build the segment there — where it's much more efficient — and then pull the result (a much smaller list) into Chatarmin. **Step-by-step:** 1. Go to **Klaviyo → Lists & Segments** and create a new Segment 2. Use the condition: **"Has property: WhatsApp Opt-In = true"** (this data is synced by Chatarmin automatically) 3. Add any additional exclusion conditions directly in Klaviyo (e.g. exclude email subscribers, inactive contacts, etc.) 4. Save the segment in Klaviyo — it will now only contain contacts who are WhatsApp opted-in 5. In Chatarmin, go to [**Audience → Segments**](https://chatarmin.com/dashboard/audience/segments) and select this Klaviyo segment to **include** it in your campaign > 💡 **Why this works better:** Instead of pulling 300,000 profiles into Chatarmin and filtering there, you're doing the filtering in Klaviyo first. The resulting "WA Only" segment will be significantly smaller and syncs quickly. *** ## Troubleshooting *** **My Klaviyo segment is not loading / showing no contacts** The most likely cause is that the segment is too large. Try the following: * Check the segment size in Klaviyo first * If it has more than \~50,000 profiles, use the approach described above and build a pre-filtered segment directly in Klaviyo * Reload the Chatarmin page and wait — large syncs can take several minutes **I built a segment in Klaviyo but it doesn't appear in Chatarmin** * Make sure your Klaviyo API key is connected in Chatarmin under **Settings → Integrations → Klaviyo** * Try logging out and back in to Chatarmin * Try a different browser (Chrome is recommended)