If you're looking to import CSV or Excel files into Google Sheets without the usual headaches, you've probably come across both SmoothSheet and Coupler.io. They both promise to make your life easier, but they solve fundamentally different problems. Picking the wrong one could mean paying for features you don't need—or missing the one feature that matters most.
This comparison breaks down exactly where each tool shines, where it falls short, and which one makes the most sense for your specific workflow.
Key Takeaways:SmoothSheet is built for importing large CSV/Excel files into Google Sheets; Coupler.io is built for syncing live data from 400+ business apps.SmoothSheet processes files server-side, so imports with 100K+ rows won't crash your browser.Coupler.io's paid plans start at $24/month and scale up to $199+/month based on connections; SmoothSheet is a flat $9/month.SmoothSheet preserves your existing Google Sheets formulas during imports—Coupler.io overwrites the destination range.Many teams use both tools together: Coupler.io for automated app syncing, SmoothSheet for heavy file imports.
The Core Difference: File Imports vs. App Integrations
Before diving into features, it's important to understand that these two tools were built for very different jobs.
SmoothSheet is purpose-built for one thing: importing large CSV and Excel files into Google Sheets reliably, without browser crashes. It processes files server-side, handles smart column mapping, and preserves your existing formulas. If your main pain point is getting big files into Sheets, this is the tool.
Coupler.io started as an Airtable-to-Google-Sheets connector in 2020 and has since grown into a full data integration platform with 400+ app connectors. It pulls data from tools like HubSpot, Shopify, Google Ads, and QuickBooks directly into your spreadsheets on automated schedules. If you need to sync live data from business apps, that's Coupler's territory.
Think of it this way: SmoothSheet is your heavy-duty file forklift. Coupler.io is a pipeline system connecting your apps together.
Feature-by-Feature Comparison
| Feature | SmoothSheet | Coupler.io |
|---|---|---|
| Primary Use | CSV/Excel file imports to Google Sheets | App-to-spreadsheet data syncing |
| Large File Handling | ✅ Server-side processing, 100K+ rows | ⚠️ Limited by browser and API rate limits |
| Smart Column Mapping | ✅ Automatic with preview | ⚠️ Basic column selection |
| Formula Preservation | ✅ Automatically extends formulas to new rows | ❌ Overwrites destination range |
| Auto Backup/Rollback | ✅ Snapshot before every import | ❌ No built-in rollback |
| Pricing | $9/month flat | Free tier available, paid from $24/month |
| Learning Curve | Minimal — drag, drop, done | Moderate — requires configuring data flows |
| Best For | Teams importing CSV/Excel reports regularly | Teams syncing live data from multiple SaaS apps |
Where SmoothSheet Wins
Handling Massive Files Without Crashing
This is SmoothSheet's bread and butter. If you've ever tried to import a 200MB CSV into Google Sheets and watched your browser freeze, you know the pain. Google Sheets processes everything client-side, which means your browser has to load, parse, and transmit every single cell. For large files, that's a recipe for the "Page Unresponsive" error.
SmoothSheet sidesteps this entirely by processing files on its own servers. Your browser never touches the raw data. The result? Files with hundreds of thousands of rows import smoothly without any crashes. Keep in mind that Google Sheets itself has a 10 million cell limit, so you'll want to check your file dimensions before importing—our free Google Sheets Limits Calculator can help with that.
Coupler.io can import CSV files too, but it wasn't designed for heavy file processing. It's built around API connections, not file-based workflows.
Formula Preservation
Here's a scenario that happens constantly: you have a Google Sheet with calculated columns—VLOOKUP formulas, IF statements, percentage calculations—all set up perfectly. You need to import fresh data every week without breaking those formulas.
SmoothSheet detects your existing formulas and automatically extends them to cover new rows. Your calculations stay intact, every time. With Coupler.io, importing data typically overwrites the destination range, which means you'd need to rebuild or manually reapply your formulas after each sync.
This is especially painful if you're working with files that need merging from multiple sources—you don't want to re-do formula work every single time.
Simplicity and Price
At $9/month with a flat pricing model, SmoothSheet is straightforward. There's no connection counting, no user limits to worry about, and no surprise costs when your data volume grows. The workflow is dead simple: drag your file, preview the mapping, and import.
Where Coupler.io Wins
Multi-Destination Support
Beyond Google Sheets, Coupler.io can send data to Excel, BigQuery, Power BI, Looker Studio, and other destinations. If you're building a more complex data infrastructure across multiple tools, Coupler.io offers that flexibility.
Pricing Breakdown: SmoothSheet vs Coupler.io
Pricing is where these tools differ dramatically, and it's worth understanding the details before committing.
SmoothSheet keeps it simple: one plan at $9/month. That gives you unlimited imports, server-side processing, formula preservation, and automatic backups. No tiers, no connection limits, no per-user fees. What you see is what you pay.
Coupler.io uses a tiered model based on the number of data connections you need:
| Plan | Price (Monthly) | Connections | Users |
|---|---|---|---|
| Free | $0 | 1 | 1 |
| Personal | From $24 | 3–5 | 1 |
| Professional | ~$199 | 25 | 2 |
| Team | ~$449 | 100 | 5 |
| Business | Custom | 400 | Unlimited |
The important thing to note is that Coupler.io charges per data connection, not per data source. That means if you have five different Google Ads accounts, each one counts as a separate connection. For teams with complex reporting setups, costs can escalate quickly. Annual billing offers around 25% off these prices.
If your only need is getting large CSV and Excel files into Google Sheets reliably, paying $24–$199+/month for app integration features you won't use doesn't make sense. SmoothSheet's flat $9/month covers everything for file-based workflows.
When to Choose SmoothSheet
SmoothSheet is the right choice if you:
- Regularly import large CSV or Excel files into Google Sheets
- Experience browser crashes or freezes during imports
- Need to preserve existing formulas when adding new data
- Want a simple, affordable tool without complex configuration
- Work with data exports from systems that don't have direct API connectors
Common use cases include finance teams importing monthly reports, operations teams consolidating data from multiple CSV exports, and analysts working with large datasets that exceed Google Sheets' comfortable handling capacity. If you're regularly working with files that need cleaning before import, SmoothSheet's free CSV Validator and Excel to CSV Converter can help you prep your data beforehand.
When to Choose Coupler.io
Coupler.io is the right choice if you:
- Need to sync live data from SaaS applications like HubSpot, Shopify, or Google Ads
- Want automated, scheduled data refreshes without manual work
- Build dashboards that pull from multiple business tools
- Need to send data to destinations beyond Google Sheets (BigQuery, Power BI, etc.)
- Are comfortable with a higher price point for broader functionality
Can You Use Both?
Absolutely—and many teams do. The two tools complement each other well. Use Coupler.io to automate your live data feeds from business applications, and use SmoothSheet when you need to import large file-based datasets that would crash your browser.
For example, a marketing team might use Coupler.io to pull Google Ads performance data into a dashboard sheet automatically, while using SmoothSheet to import a massive customer list export from their CRM that comes as a 500MB CSV file. If that CSV needs splitting first, the free CSV Splitter can break it into manageable chunks.
Frequently Asked Questions
Is Coupler.io free?
Coupler.io offers a free plan, but it's limited to just one data connection and one user. For most business use cases, you'll need a paid plan starting at $24/month. There's also a 7-day free trial on the Pro plan so you can test premium features before committing.
Can SmoothSheet sync data from apps like HubSpot or Shopify?
No. SmoothSheet is designed exclusively for file-based imports—CSV and Excel files that you upload manually. If you need automated data syncing from SaaS applications, you'll need a tool like Coupler.io or a custom Google Apps Script solution.
Which tool is better for large CSV files over 100MB?
SmoothSheet is significantly better for large files. It processes imports server-side, so your browser doesn't have to handle the heavy lifting. Coupler.io is primarily designed for API-based data flows and doesn't specialize in processing large local files.
Does SmoothSheet work with Excel files or only CSV?
SmoothSheet supports both CSV and Excel files (XLSX and XLS formats). It handles the conversion and import seamlessly, preserving your data structure and extending existing formulas in your destination sheet.
Can I use Coupler.io to import a CSV file into Google Sheets?
Yes, Coupler.io has a CSV importer, but it's not its primary strength. For one-off or occasional CSV imports, Google Sheets' built-in import works fine. For large or frequent CSV imports that crash your browser, SmoothSheet is the more specialized and affordable option at $9/month.
The Bottom Line
This isn't a question of which tool is "better"—it's about which problem you're solving. If large file imports are your bottleneck, SmoothSheet at $9/month is the most focused and affordable solution available. If you need automated data pipelines from dozens of business apps, Coupler.io's broader platform is worth the higher investment.
The worst choice is using the wrong tool for the job. Pick the one that matches your actual workflow, and you'll wonder how you ever managed without it.