A viewer that keeps up
A virtualized grid renders millions of rows without breaking a sweat. Sticky headers, resizable columns and automatic type detection make raw exports readable.
Your files never leave your device
Open huge CSV, Excel and JSON files right in your browser
SheetPeek is a local-first viewer and analyzer for big, messy data files. Filter, sort, profile, dedupe, diff and export millions of rows — without uploading a single byte.
Drop a file here, or click to browse
.csv · .tsv · .xlsx · .xls · .json — it stays on this device
No upload · No signup · Free
Everything the “quick look” actually needs
Built for accountants reconciling ledgers, analysts sampling raw exports, developers eyeballing data dumps, and store owners cleaning product feeds.
Filter and sort anything
Global search across every cell, per-column operators like contains, between and is empty, plus multi-column sort with shift-click. All computed locally, in the background.
Hunt down duplicates
Pick the columns that define “the same record” and SheetPeek groups every duplicate for review — then exports a deduplicated copy that keeps the first of each.
Instant column statistics
Counts, empties and distinct values for every column; min, max, mean, median and sum for numbers; top-10 value frequencies for everything else.
Compare two files
Diff yesterday’s export against today’s by any key column. See exactly which rows were added, removed or changed — down to the individual cell.
Export any view
Whatever you’re looking at — a filtered slice, a dedup result, a diff bucket — leaves as clean CSV, XLSX or JSON with one click.
Privacy by architecture
0 bytes uploaded. Ever.
Most “online CSV viewers” are upload forms in disguise. SheetPeek is different by construction: the entire engine — parsing, filtering, statistics, comparison, export — is code that runs inside your browser tab. There is no server that could receive your data, so client lists, payroll exports and medical spreadsheets stay exactly where they belong: on your machine.
- Parsing happens on your device. CSVs stream through a background worker thread; Excel and JSON are decoded in-memory.
- Works offline. Once the page is loaded you can pull the network cable and keep analyzing.
- Nothing to breach. No accounts, no stored files, no processing queue holding a copy of your data.
Network activity while analyzingLocal only
- Bytes uploaded
- 0
- Rows it can chew
- 10M+
- Accounts required
- 0
- Price
- Free