When SplitForge Fits — and When It Doesn't
Analysis Speed by Dataset Size
ANALYZE_WORKBOOK operation only (issue detection + column profiling). Cleaning operations add overhead — see Operation Overhead section below.
| Dataset | Analysis time | Rows/sec | Source |
|---|---|---|---|
| 10K rows | 0.303s | 33.0K/sec | Calculated from baseline |
| 50K rows | 1.52s | 32.9K/sec | Calculated from baseline |
| 100K rows | 3.03s | 33.0K/sec | Calculated from baseline |
| 200K rows | 5.7s | 35.1K/sec | Verified (median of 3 runs) |
| 400K rows | 12s | 33.3K/sec | Verified (median of 3 runs) |
Test configuration: Chrome (Headless 127), Windows 11 x64, July 2026. Median of 3 runs. ANALYZE_WORKBOOK operation only — the file is read and the first ~1,000 rows are sampled for profiles and issue counts; no cleaning applied. File: standard XLSX with mixed text, numeric, and date columns. Results vary by hardware, browser, and file complexity (±15–25%).
Operation Overhead Relative to Analysis
How much longer each cleaning operation takes compared to the analysis baseline (1.0×). Operations are additive — running four operations multiplies accordingly.
| Operation | Overhead factor | Speed class | Est. time (400K rows) |
|---|---|---|---|
| Analyze workbook (baseline) | 1× | fastest | ~12s |
| Remove empty rows/columns | 1.1× | fastest | ~13s |
| Trim whitespace | 1.2× | fastest | ~14s |
| Strip cell formatting | 1.3× | fastest | ~16s |
| Flatten formulas | 1.5× | fast | ~18s |
| Normalize date formats | 2× | fast | ~24s |
| Fix mixed-type columns | 2.2× | fast | ~26s |
| Remove merged cells | 2.5× | fast | ~30s |
| Find & replace | 1.4× | fastest | ~17s |
| Standard deduplication1 | 4× | moderate | ~48s |
| Fuzzy deduplication (Levenshtein, first 5K rows)1 | 40× | slow | 15–90 min |
¹ Standard and fuzzy deduplication overhead factors measured from internal testing, July 2026 (same hardware and methodology as analysis baseline). Fuzzy dedup uses Levenshtein distance — O(n²) worst case. Actual timing varies significantly by data entropy and threshold setting (0.50–0.99). All other operation factors are internal estimates based on profiling; treat as indicative ranges, not guaranteed values.
Verified Benchmarks
The two measured anchor points (ANALYZE_WORKBOOK — file read + sampled analysis). Median of 3 runs; HeadlessChrome (stable), Windows 11 x64, July 2026. Results vary by machine.
Verify It Yourself in DevTools
Open Chrome DevTools before you drop a file in. Go to Network. Filter by "XHR" or "All". Drop your file. Run a full clean. You will see zero outbound requests to any external endpoint. The file is read by the browser's File API, processed in a Web Worker thread, and never serialized to any network call.
No server endpoint exists in this tool's architecture.
DevTools screenshots pending production capture. You can run this verification yourself on any file — the architecture makes the claim auditable by anyone.
Test Methodology
Hardware Configuration
Test Protocol
Variability disclosure: Results vary by hardware, browser, and file complexity (±15–25%). Older CPUs, systems with less RAM, or files with more complex data structures (deep nesting, many merged regions, high duplicate density) will see higher times. The 400K-row verified benchmark represents a modern hardware configuration — treat as an upper-bound reference, not a guaranteed result.
Time Value Calculator
Estimate the time and cost difference between manual cleaning and SplitForge.
Assumes ~40 seconds per file (100K-row standard clean, no fuzzy dedup). Actual time varies by file size, operations selected, and hardware.
Performance Limitations
Excel Input Cap (~20 MB / ~440K rows)
Excel Cleaner reads the entire workbook into memory (SheetJS materializes ~240 bytes per cell), so it caps Excel input at ~20 MB (about 440,000 rows). Larger Excel files exhaust the browser tab and can crash it, so they are rejected before the read.
Fuzzy Dedup Capped at 5,000 Rows
Fuzzy deduplication is an O(n²) algorithm (at 100K rows that is ~10B comparisons). Because of this cost it is capped at the first 5,000 rows — a live banner discloses when your file exceeds that. Exact deduplication has no such cap and processes the full file.
No Batch or Automation Support
SplitForge is a manual, one-file-at-a-time tool. No API, no CLI, no file watcher, no scheduled runs. It cannot be integrated into CI/CD pipelines, cron jobs, or server-side workflows.
External Formula References Cannot Be Flattened
Formulas referencing other workbooks (e.g., =[Budget.xlsx]Sheet1!A1) cannot be evaluated or flattened — the referenced files are not available in the browser context. Cells with unresolvable references will be cleared or preserved as-is depending on your settings.
Performance Questions
How was the ~33,000 rows/sec figure measured?
Why does my file process slower than the benchmark?
What is the maximum file size supported?
Why is fuzzy deduplication so much slower than everything else?
Does the browser tab need to stay open during processing?
How does performance compare to Python pandas?
Can I reproduce these benchmarks on my own machine?
What happens to performance when running multiple operations together?
The Benchmark Is Public. Reproduce It.
Drop your own file in. Open DevTools. Time it yourself. That's the level of transparency we're building toward.
Also try: Excel Splitter · Data Masking · Data Profiler · Remove Duplicates · View All Features