Two files in.
One clear answer out.
Contracts, configs, workbooks, screenshots — Diffesq shows exactly what changed, without your files ever leaving the machine.
or · drop two files together to fill both slots
Private by design — files are never uploadedfree for text & Markdown · no account
| Row | Region | Q1 | Q2 | Δ |
|---|---|---|---|---|
| 4 | EMEA | 418,200 | 440,090 | — |
| 5 | APAC | 318,400 | modified | |
| 6 | LATAM | 96,310 | 104,882 | added |
| 7 | NA | 712,004 | 699,850 | — |
How it stays private
Your files never leave your machine.
Runs in your browser
Parsing, diffing, and rendering all happen locally — turn off Wi-Fi and it still works.
No account, no upload
There is no server to send files to and nothing to sign up for. Drop, read, done.
Reports made locally
Exports — HTML, Markdown, JSON, PDF — are generated on your device, watermark-free with Pro.
New — Delta charts
See the shape of the change.
Any numeric column in a spreadsheet or CSV flips into a delta chart — values on one axis, the change itself on the other. Spot the outlier before you read a single row.
Illustration: an example delta chart of revenue by region. EMEA, APAC, LATAM and MEA rose; NA fell. The figures are summarised beside it.
Net change
+33,958
+2.1% across 5 regions
New — GeoJSON maps
Watch the map move.
Drop two GeoJSON files and they become one 3D map: added, removed and reshaped features stacked as before-and-after layers you can orbit and pick apart. This is lower Manhattan, 2024 against 2026.
Illustration: an example 3D comparison of lower Manhattan lot boundaries, 2024 against 2026, drawn as two stacked layers. 4 lots were added, 3 removed and 7 redrawn; the figures are summarised beside it.
Features changed
14 lots
of 87 in the 2026 file
Beyond single files
Folders and image libraries, too.
Point Diffesq at two directory trees and review every difference in one pass — or scan a photo library for duplicates it finds by looking, not hashing.
Purpose-built views
Every format, its own view.
A redline is not a cell grid is not a pixel overlay. Diffesq picks the right reading surface the moment it recognises the file.