The n8n Merge Node Explained: Combine Data from Multiple Sources (2025)
Sooner or later every n8n workflow needs to pull two streams of data back together — a customer record from your CRM joined with their orders from a database, or results from three APIs combined into one report. That's the job of the Merge node. Here's how each mode works.
Why you need Merge
n8n runs branches in parallel. When you split a workflow — say, one branch hits HubSpot and another hits Stripe — you end up with two separate sets of items. The Merge node reunites them so downstream nodes see a single, combined dataset.
The three main modes
1. Append
Stacks the items from all inputs into one list, one after another. Use it when you're gathering similar records from multiple sources — e.g. leads from Typeform and leads from a webhook — and just want them in one pile.
2. Combine by Matching Fields (join)
This is the SQL-style join. Pick a key that exists in both inputs — email, customer_id, order_number — and Merge pairs up matching items, enriching one record with fields from the other. Choose whether to keep unmatched rows (like a LEFT or OUTER join).
3. Combine by Position
Pairs the first item of input 1 with the first item of input 2, and so on. Handy when two branches return records in a guaranteed matching order.
🚀 Skip the build — get the ready-made template
This article shows you how it works. The Data Analytics AI Agent template gives you the finished n8n workflow — import it, add your credentials, and go live today.
Get Data Analytics AI Agent on Gumroad →
SQL mode for power users
The Merge node can also run a full SQL query across its inputs, treating each as a table. This unlocks complex joins, filtering, and aggregation without a Code node — ideal when you're assembling a report from several sources.
Common pitfalls
- Empty output — if the matching key doesn't exist or is spelled differently in each branch, nothing matches. Log both inputs first.
- Waiting for both inputs — Merge waits for all connected inputs to finish. If one branch errors, the merge may never run. Add error handling upstream.
Put merged data to work
Combining sources is the foundation of reporting. Once you can join GA4, HubSpot, and Google Sheets in one workflow, an AI data analytics agent can turn that merged dataset into a plain-English narrative of what changed and why — delivered to your inbox every morning.
Ready to automate?
Don't rebuild this from scratch. The Data Analytics AI Agent template is a complete, importable n8n workflow — configure your credentials and it runs in minutes.
