SplitForge

Professional CSV & Excel Tools

Split, merge, remove duplicates, find & replace, manage columns, and convert between CSV and Excel formats.

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Real-World Performance Benchmarks

15 Million Rows.
67 Seconds. In Your Browser.

All tools process files client-side in your browser using Web Workers and streaming architecture. Zero uploads, zero data exposure.

Benchmarks conducted by SplitForge engineering team. Results vary by hardware, browser, and file complexity (±15–20%).

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Runs locally · No file upload · Chrome (stable) / Win 11 · See methodology

Featured Benchmark

CSV Splitter

102M rows (10 GB)

View Full Benchmark

How We Achieve These Numbers

Streaming Architecture

Process files chunk-by-chunk without loading entire datasets into memory

Client-Side Processing

All computation happens in your browser - your data never leaves your device

Web Workers

Multi-threaded processing keeps UI responsive even with massive files

Optimized Algorithms

FNV-1a hashing, binary operations, and zero-copy buffers for maximum speed

Tool Performance Overview

CSV Tools

CSV Merger

No ceiling — 40 MB heap

Remove Duplicates

~218–277K rows/sec (OPFS)

10 GB Gate-3 validated

Find & Replace

2M replacements

CSV Splitter

Column Operations

Complex transforms

Split Column

428M rows (proj.)

10 GB constant-memory

Format Converter

~440K rows/sec (harness)

CSV→JSONL — zero upload

Delimiter & Encoding

~303K rows/sec (proj.)

Pivot & Unpivot

200M rows (10.4 GB)

~250K rows/sec (OPFS)

Gate 3 validated

CSV Compare

50M+ rows tested

Cell-level diffs

VLOOKUP/Join

Constant ~250–390MB

Data Validator

228M rows (10GB)

~1M rows/sec (format-only)

CRM presets + uniqueness

Pattern Extraction

551K patterns found

Data Profiler

500MB / 3M rows (exact)

~12.7K rows/sec (exact)

Fast sample, any size

Data Masking

~250K rows/sec (proj.)

PII anonymization

Aggregate & Group

200M rows (10.4 GB)

~235–270K rows/sec (OPFS)

Gate 3 validated · 19 functions

Data Cleaner

Memory-bounded streaming

No memory ceiling

Excel Tools

Excel Splitter

20 sec processing

Excel CSV Converter

~31.5K rows/sec

~6.3 sec (200K rows)

Excel JSON Converter

XLSX ~14 MB/file

array-of-objects

pretty / minified / multi-sheet

Excel Cleaner

~12 sec (400K rows)

Excel Sheet Extractor

5.7 sec processing

Excel Compare

~200K rows/file

~12.8K rows/sec

~15.6 sec (2×200K)

Excel Column Extractor

~9.5 sec (200K rows)

Excel Sheet Merger

XLSX ~14 MB/file

~20 MB aggregate

5 merge modes · CSV streams

Excel Repair

Formula preservation

Excel Preview

Any size (subset)

~45K rows/sec (<12 MB)

Instant 1,000-row preview

Benchmark Methodology

All benchmarks run via automated harness (scripts/stress-test-tool.js) using Puppeteer-controlled Chrome with --enable-precise-memory-info. GC forced before each run via HeapProfiler.collectGarbage. Best of 3 runs per tier (lowest peak reported). Test files generated via scripts/gen-test-files.js with deterministic seeds.

Machine

dev machine (Alder Lake class), 64 GB RAM

OS

Windows 11, SSD

Browser

Chrome (stable)

CSV Splitter test date

June 2026 (TRUE 10GB)

Reproducibility: all test scripts are in the SplitForge repository. Anyone can re-run these benchmarks on their own machine with the same scripts and deterministic test files.

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Drop any file into any tool. No signup, no upload, no waiting. Processing starts the moment you select a file.

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