Sample files for performance and load testing
Large, predictable inputs for measuring throughput, memory use and processing time.
Performance problems in file handling are rarely visible with small inputs. Memory use that is negligible at 10 KB becomes an outage at 10 MB if the code reads whole files into memory, and a parser that seems instant can turn out to be quadratic.
Testing with a ladder of sizes, each ten times the last, shows how time and memory grow. If a tenfold increase in input costs much more than a tenfold increase in time, there is something to fix.
Recommended files
| File | Size | Why this one | Download |
|---|---|---|---|
| 10 MB CSV samplesample-csv-10mb.csv | 10 MB10,485,760 bytes | Import throughput | Download CSV |
| 10 MB JSON samplesample-json-10mb.json | 10 MB10,485,760 bytes | Parser memory use | Download JSON |
| 10 MB XLSX samplesample-xlsx-10mb.xlsx | 10 MB10,485,760 bytes | Spreadsheet import with hundreds of thousands of rows | Download XLSX |
| 10 MB JPG samplesample-jpg-10mb.jpg | 10 MB10,485,760 bytes | Image decode memory | Download JPG |
| 10 MB BIN samplesample-bin-10mb.bin | 10 MB10,485,760 bytes | Network throughput | Download BIN |
Checklist
Measure a size ladder
Run the same operation on 100 KB, 1 MB and 10 MB files and compare how time and peak memory scale.
Watch memory, not only time
Peak memory several times the file size indicates buffering or a DOM-style parser.
Test concurrency
Ten simultaneous 10 MB uploads behave very differently from one. Check queueing, back-pressure and temporary disk use.
Use incompressible data for network tests
Text files flatter your numbers when compression is enabled.
Guides
- How to test file size limits
Where upload limits live, what the common defaults are, and how to test a boundary to the byte.
- How to test file downloads
Completeness, integrity, speed, range requests and resume, each with a command you can run.
- How to create test files of any size
Commands for Linux, macOS and Windows that produce a file of an exact byte count, and when to use each.
Related use cases
Frequently asked questions
- How large an image does the 10 MB JPG decode to?
- Its pixel dimensions are listed on the download page. Multiply width by height by four to estimate the bytes of memory needed to hold it decoded.