Create a Large CSV File
Generate a large CSV file for testing. Runs entirely in your browser, so your data never leaves your device.
Output
The result appears here as you type.
How to use Create a Large CSV File
- 1. Set the target size. No input file is needed; choose a number for Target size and pick KB or MB as the Unit. The generator emits random rows until the file reaches approximately that size.
- 2. Shape the rows. Columns controls how wide each record is. More columns means fewer, longer rows for the same byte count; fewer columns means many short rows, which stresses parsers differently.
- 3. Download the big file. Click download to save large.csv. Generation happens in your browser, so producing a multi-megabyte test file requires no server, script or dataset hunting.
When to use Create a Large CSV File
Create a Large CSV File generates bulk test data at a size you specify, from a few kilobytes to many megabytes. Performance problems hide until real volume arrives, and this tool lets you manufacture that volume on demand instead of scavenging for big datasets.
- Stress-testing an upload pipeline. Your service accepts CSV uploads up to 10 MB. Generate files at 9, 10 and 11 MB to verify the limit enforcement, timeout behavior and error messages at the boundary.
- Benchmarking parser performance. Comparing two CSV libraries requires identical-scale input. Generate a 50 MB file once and time both implementations against it for a fair measurement.
- Testing streaming versus buffering. Code that reads a whole file into memory works fine on samples and dies on production exports. A generated large file exposes the memory spike in development.
- Checking UI behavior on big tables. A data grid component claims to handle huge files with virtual scrolling. Feed it a generated multi-megabyte CSV and watch the frame rate before believing the docs.
Examples
A 1 MB test file
Output
A downloadable large.csv of random rows, about 1 MB in size.
About the Create a Large CSV File tool
Create a Large CSV File does its work locally, right in the browser. Generate a large CSV file for testing. There is no upload step, no queue and no account, and your data never travels over the network.
It belongs to the CSV Tools collection on EditSafely, a set of 133 small, focused CSV utilities that share the same instant, private workspace.
You can shape the output with 3 settings, including Target size, Unit and Columns, and the result refreshes the moment you change one. The finished file is put together in browser memory and saved with the Download button, so it never touches a server on the way to your disk. A worked example further down the page shows exactly what the tool produces for a real input.
Running locally also makes the tool fast and dependable: results appear as you type or drop a file, there is no server outage that can take it down mid-task, and confidential data can be processed without a second thought.
Frequently asked questions
Is Create a Large CSV File free to use?
Yes, it is completely free. All 2,658 tools on EditSafely work without an account, a subscription or usage limits.
Does the generator send anything to a server?
Everything happens locally. Your browser downloads the tool's code once, then does all the processing itself; nothing you enter is transmitted, stored or logged. You can even go offline after the page loads and it will still work.
How do I get a different result?
Run the generator again. Each run is computed fresh on your device, and any options you change are applied to the next result immediately.
Do I need to sign up or install anything?
No. The tool works in any modern browser on desktop, tablet or phone. There is no account to create, no extension to add and no software to install.
How do I save the output?
Click the Download button once the result is ready. The file is built in your browser's memory and handed straight to your downloads folder, without passing through a server.