A VS Code extension that lets you view and edit JSONL (and legacy .ndjson) files in a spreadsheet-like grid powered by AG Grid.
Features
Spreadsheet UI -- Open .jsonl or .ndjson files and browse them as a sortable, filterable, resizable grid.
Inline editing -- Click a cell to edit values. Changes are saved back to the original file with full Undo / Redo support.
Subtable expansion -- Nested arrays of objects (sub-tables) can be viewed in four modes:
| Mode | Description |
|------|-------------|
| Modal | Pop-up overlay with its own grid |
| Docked | Bottom panel attached to the main view |
| Inline | Embedded grid row inserted below the parent row |
| Flat | Sub-records expanded directly into the main grid as regular rows |
Bulk expand -- Inline All / Flat All buttons in the toolbar to expand every subtable at once.
Search -- Quick-filter search with match navigation (Enter / Shift+Enter).
Theme aware -- Follows your VS Code light / dark theme automatically.
Chunked loading -- Large files are loaded in 500-row chunks with virtual scrolling, so the UI stays responsive.
Supported file types
Extension
MIME
.jsonl
application/jsonl
.ndjson
application/x-ndjson (legacy, supported)
Getting started
Install the extension from the VS Code Marketplace.
Open any .jsonl or .ndjson file -- the grid editor opens automatically.
Click the > button in a subtable cell to expand it. Use the mode-cycle buttons to switch between Modal, Docked, Inline, and Flat views.
Edit cells directly. Press Ctrl+S / Cmd+S to save.
