Private Browser Spreadsheet — XLSX and CSV

Spreadsheets and drawings, off the cloud

The tools in this cluster work on data you would rather not treat as disposable: a financial model, a set of construction drawings, a design system that took months to build. Their “free online” counterparts usually want the file on a server — and often want you to keep it there. FigCraft, CADCraft and GridCraft work from the other direction: everything is parsed, edited and exported inside the browser tab.

GridCraft is the spreadsheet: it opens and saves XLSX, reads CSV, TSV and JSON, keeps formulas, dynamic arrays, PivotTables and charts working, and exports a PDF table for sharing. CADCraft is the drafting tool: it opens DXF and DWG files from R12 through 2018, with a command line, object snaps, layers and dimensions, and exports DXF, SVG or a PDF blueprint. One honest limit: DWG files open but are not written back as DWG. FigCraft is the interface design tool — frames, auto layout, components and variants — with exports that are code as much as pictures: CSS tokens, JSON design tokens, SVG and PNG at 1×, 2× and 3×.

Every cell in the format table below comes from the same record the app pages publish, so the limits are printed rather than discovered.

What local-first means for your data

Spreadsheets and drawings are where cloud tools quietly become the only copy — auto-saving into an account you did not plan to create, under a sharing model you did not choose. Here, saving is an export: the file lands on your disk, in the format you picked, with no account, no upload and no vendor copy. For anyone working under confidentiality terms, that is not a convenience — it is the difference between using a tool and being unable to.

What these apps open and save

App	Opens	Saves
FigCraft	SVG · JSON tokens · FigCraft (.figcraft)	CSS tokens · SVG · PNG (1x/2x/3x) · JSON design tokens
CADCraft	DXF · DWG (R12 to 2018) · SVG · STEP (basic)	DXF · PDF blueprint · SVG
GridCraft	XLSX · CSV · TSV · JSON	XLSX · CSV · PDF table

Every cell is read from the same format record the app pages print; where a format only travels one way — PSD or DWG, for example — the table says so rather than implying a round-trip.

The data apps on Plasa.app

FigCraft

UI / UX interface design

Interface design, rebuilt in pure Rust.

CADCraft

CAD & technical drafting

Computer-aided design and drafting, reimagined in pure Rust.

GridCraft

Spreadsheets & analysis

Fast, native spreadsheets, rebuilt in pure Rust.

Frequently asked questions

Can I open an Excel file in the browser without uploading it?+

Yes. GridCraft opens XLSX files — and CSV, TSV and JSON — directly from your disk, with formulas, dynamic arrays, PivotTables and charts, then exports XLSX, CSV or a PDF table. Nothing is uploaded and no account is needed.

Can I open a DWG file without AutoCAD?+

CADCraft opens DXF files and DWG files from R12 through 2018 in the browser, and exports DXF, SVG or PDF blueprints. One honest limit: DWG opens but is not written back as DWG — the full export list is in the format table on this page.

Does the design tool export code, or only images?+

Code is the interesting part. FigCraft exports CSS tokens and JSON design tokens from your design system, plus SVG and PNG at 1×, 2× and 3× for assets and handoff.

Are my spreadsheets and drawings sent to a server?+

No. All three apps run entirely in your browser as WebAssembly — files are read from your disk, processed locally and saved back by you. The architecture is documented at plasa.app/privacy.