Open large CSV files.
Keep your data on your computer.
Inspect, filter, merge, split, and summarize CSV exports in a visual desktop app. Turn an oversized file into the result you need—without uploading it for core processing.For finance, operations, and anyone working with messy exports.
See the actual desktop workflow: open a file, inspect it, and prepare your result.
Your files. Your workflow.
What is DataOlllo?
DataOlllo is a local-first desktop app for teams that need to open, clean, merge, split, filter, and summarize files that are too large for spreadsheet-style workflows or too sensitive for cloud upload. Analysts use it when exports from finance systems, ad platforms, healthcare tools, storefronts, logistics logs, or research instruments exceed normal worksheet limits, create privacy risk, or require repeatable cleanup before reporting. Instead of uploading raw customer, patient, transaction, or operational data to a browser tool, DataOlllo keeps processing on the workstation and gives users visual workflows for large CSV, JSON, and structured files. It is built for practical operations work: inspect columns, reduce messy data, combine recurring folders, and prepare analysis-ready outputs while keeping sensitive source files under local control. For context, Microsoft documents fixed spreadsheet row and column limits; DataOlllo is designed for workflows beyond those limits.
A practical first session
From raw export to useful result.
Start with a copy of a familiar CSV. Inspect its columns and sample rows, filter a date range or category, then export the selected result. Compare the output with your original before using it in a report.
Need the same preparation next week? DataOlllo supports saved workflows and processing folders of recurring exports. Combine files, group and summarize values, and review results before export. Explore repeatable workflows.
Built for Large CSV Work.
Open, inspect, filter, merge, split, and summarize big files without sending them away.
The Speed Problem
Inspect the source, select useful rows and columns, and export a smaller result. Capacity and speed depend on your hardware, file structure, and the operation you choose.
The Privacy Problem
Cloud tools can be blocked by upload limits, policy rules, or sensitive columns. DataOlllo runs local analysis on your device, with optional AI workflows designed around private data handling.
The Cleanup Problem
Large, messy datasets from sales, finance, healthcare, logs, or research are hard to clean, merge, and analyze. DataOlllo gives you visual workflows for big files without writing scripts.
Start with the problem you have.
Practical guides for oversized CSV files, upload limits, local workflows, and private analysis.
What do you need to fix today?Select a workflow to see how we handle it.
View all featuresAd Report Merger
Combine recurring CSV exports, check matching columns, and prepare a consistent report.
Bank Reconciliation
Compare statement files, payment records, and exported CSVs to investigate missing transactions.
Data Cleanup & Analysis
Clean, group, and filter structured exports locally. Keep data handling aligned with your organization’s policies.
And yes,
it talks.
Don't want to write scripts? Just ask.
"Merge these files and show me the profit by Q3"
Core CSV preparation works locally. AI features may use online services depending on your configuration. Review the privacy details before using sensitive data.
Try AI Analysis
Your data is waiting.
Download NowFree for personal use • Windows 10/11 • MacOS • Built for large CSV files