I’m pretty new to Google Sheets scripting but have been working with spreadsheets more lately. I need to set up two different Google Sheets files where one can pull data from the other, kind of like how VLOOKUP works but across separate documents.
The reason I need separate files is because my datasets are really big and putting everything in one spreadsheet makes it too slow. I tried using IMPORTRANGE but it has a limit of 50 imports per sheet and that’s not enough for what I’m doing.
What I want is to be able to fetch just one piece of data at a time from the source spreadsheet without having to display it permanently in cells. I’m thinking Google Apps Script might be the way to go but I’m still learning the basics.
Speed is really important here because I’m dealing with tons of data. I used to have around 1500 VLOOKUP formulas and it was getting super slow until I reduced them.
Is this possible with scripting? What specific functions should I look into? I can figure out the implementation details myself, I just need to know which direction to go.
Google Apps Script is your best bet here. Use SpreadsheetApp.openById() to grab your external spreadsheet and getRange().getValues() to pull specific data without permanent cell references. I ran into the same performance issues with large datasets - caching saved my life. Use CacheService to store frequently accessed data for up to 6 hours. It cuts down API calls to the source spreadsheet like crazy. For data that doesn’t change much, try PropertiesService instead. Watch out for the 6-minute execution limit per script run. If you’re processing tons of data, you’ll need batching or LockService with time-based triggers to split the work across multiple runs. The big win over IMPORTRANGE? You only fetch what you actually need instead of maintaining live connections that bog everything down.
Hit this same wall last week. Skip the fancy stuff - onDemand() does the job perfectly. Use getValue() for single cells instead of getValues() - way less overhead. Pro tip: SpreadsheetApp throttles automatically, so don’t stress about hitting limits. Just wrap everything in try-catch blocks for when sheets get busy.
Been there, done that. Google Apps Script keeps you stuck in Google’s ecosystem with those annoying execution limits.
I ditched Sheets for the heavy lifting and built a workflow in Latenode instead. It connects directly to both spreadsheets, grabs what I need on demand, and pushes it back. No more 50 import limits, 6-minute timeouts, or caching hacks.
Best part? Set triggers based on actual data changes or schedules. Someone updates the source sheet, Latenode automatically handles the lookup and updates the destination. No manual script running or formula refreshing.
I’m crushing 1500+ lookups now and it’s blazing fast since Latenode does the work on their servers, not Google’s cramped script environment.
Keep your Sheets interface while automation runs behind the scenes. Way cleaner than fighting Apps Script.
Just dealt with the same performance issues on client reports. What saved me was a hybrid approach with Apps Script and smart indexing. Instead of searching entire datasets, I built an index mapping system - the source sheet gets a separate index tab with key-value pairs. When my script needs data, it hits this lightweight index first to grab the exact row number, then fetches just that cell with getRange(row, column). No more scanning thousands of rows per lookup. The index updates automatically with onChange triggers, so it stays current without any manual work. Performance went from 45+ seconds down to 3-4 seconds for multiple lookups. Best part? Everything stays in Google’s ecosystem without the memory overhead of massive arrays. Works great when your lookup keys have predictable patterns or you can sort your source data strategically.
Had this exact problem six months ago when my inventory sheets crapped out. Built a custom Google Apps Script function that’s basically VLOOKUP on steroids - pulls from external sheets only when needed.
Here’s what worked: Used SpreadsheetApp.openByUrl() with range filtering instead of downloading entire datasets. My function takes the lookup value and column, opens the source sheet, uses findText() to locate the row, then grabs just that cell. Way faster than loading everything into memory.
Couple gotchas I learned: Add error handling for when someone else is editing the source sheet. Without it, your script randomly fails and returns blanks. Also, opening the same external sheet multiple times in one run kills your quotas, so batch your lookups.
Performance difference was huge - went from 30+ seconds down to under 5 for complex lookups.
Apps Script kept timing out on my financial lookups, so I switched tactics. Instead of hitting the external sheet every time, I pull the entire lookup table into a 2D array once using getDataRange().getValues(), then search it locally with JavaScript’s find() method. Takes 2-3 seconds upfront, but after that lookups are instant since it’s all in memory. I store the array globally so other functions can reuse it, and only refresh when I actually need new data. Completely sidesteps Google’s throttling and execution limits - response times are under 100ms now. Perfect for lookup tables that don’t change much during the day.
Apps Script works but you’re stuck managing all the complexity - memory arrays, timeouts, batch processing. It’s a maintenance nightmare.
I ditched that approach and moved my lookup logic outside Google Sheets completely. Built a workflow in Latenode that monitors both spreadsheets and fetches data automatically.
Here’s what’s great: instead of custom functions your sheets have to call, Latenode runs lookups independently and updates your destination sheet directly. No execution limits, memory headaches, or caching strategies.
Set it up once with triggers for row changes or time intervals. Someone updates your source data? Latenode processes all lookups instantly and pushes results to your working sheet. You just use the data.
Ran 2000+ cross-sheet lookups last month this way. Response time stays consistent since processing happens on dedicated servers, not Google’s shared script environment.
Your sheets stay clean and fast. Automation handles the heavy lifting.