BigSur AI Is Sunsetting: Here's the Best Alternative for Your Shopify Store

What's Happening to BigSur AI?

BigSur AI, the conversational product search tool that many Shopify merchants relied on, has announced it's winding down operations. For store owners who integrated BigSur into their customer experience, this creates an urgent need to find a replacement before the service goes offline.

The good news? The AI landscape has evolved significantly since BigSur first launched. Modern alternatives offer better conversational AI, easier setup, and more robust features. In this guide, we'll introduce you to Milly Chat—a drop-in BigSur replacement powered by Claude, Anthropic's advanced AI assistant. If you'd rather weigh the full field first, our roundup of the best Shopify live chat apps compares the leading options side by side.

Why Milly Chat Is the Best BigSur Alternative

Milly Chat was built specifically for e-commerce stores that need intelligent, conversational product search. Here's why it's the ideal replacement for BigSur AI:

• Powered by Claude Sonnet 4 — Anthropic's latest AI model provides more natural conversations, better product understanding, and more helpful responses than older AI systems.
• 5-minute setup — Install via Shopify, and your product catalog syncs automatically. No complex configuration or API integration required.
• Hybrid search — Combines semantic AI search with keyword matching, so customers find products whether they search "blue running shoes" or "comfortable sneakers for jogging."
• Real-time streaming — Responses stream word-by-word for a natural chat experience, just like talking to ChatGPT.
• Knowledge base support — Add custom content about shipping, returns, sizing, and more. The AI retrieves relevant info when customers ask.
• Direct founder support — No ticket systems or chatbots. Email us and get a response from the people who built it.

BigSur AI vs Milly Chat: Feature Comparison

How to Migrate from BigSur AI to Milly Chat

Migrating to Milly Chat is straightforward. Most merchants complete the process in under an hour, and you can run both systems in parallel during the transition.

Step 1: Sign Up for Milly Chat

Visit chat.millysoftware.com and create your account. We offer a trial period so you can test the widget on your store before committing.

Step 2: Connect Your Shopify Store

Click "Connect Shopify" and authorize the app. Milly Chat will automatically sync your product catalog, including titles, descriptions, prices, images, and inventory status. This typically takes 2-5 minutes depending on catalog size.

Step 3: Configure Your Widget

Customize your widget's appearance to match your brand:

• Choose your widget format — chat bubble, search bar, slideout panel, or smart banner
• Set your brand colors
• Write a custom greeting message
• Add AI instructions for your brand voice
• Configure quick questions for common queries

Step 4: Add Your Knowledge Base (Optional)

If you have FAQs, shipping policies, or product care instructions, add them to your knowledge base. The AI will retrieve this information when customers ask relevant questions.

Step 5: Install the Widget

Copy the embed code from your dashboard and add it to your Shopify theme. The widget works on all pages by default, or you can configure it to appear only on specific pages.

Step 6: Test and Go Live

Use the Sandbox feature in your dashboard to test conversations before going live. Once you're satisfied, enable the widget for your customers. You can use gradual rollout (10%, 25%, 50%, 100%) to monitor performance.

Tips for a Smooth Migration

• Run both systems in parallel — Keep BigSur running while you test Milly Chat. This ensures no gap in customer support.
• Transfer your best practices — If you had custom prompts or instructions in BigSur, adapt them for Milly Chat's AI Instructions field.
• Review your analytics — Check what questions customers asked most frequently in BigSur and ensure your knowledge base covers those topics.
• Test edge cases — Try queries that were problematic with BigSur. Modern AI handles nuanced questions much better.

Frequently Asked Questions