How it works

From huge file to answer in three steps.

A native, memory-mapped engine that treats your data as structure — not text.

The workflow

Open it. Navigate it. Find anything.

Every file is memory-mapped and parsed once into a compact index — only the rows on screen are ever built.

1

Open the file

Drag in a JSON, NDJSON, XML, CSV or TSV file up to ~10 GB — or paste from the clipboard or fetch a URL with auth. It opens instantly, no progress bars.

2

Navigate the tree

Everything renders as one uniform, virtualized tree. Jump to any path, bookmark nodes, and read collapsed counts like “products : […], 31 items”.

3

Search & export

Regex find, live filter, or JSONPath / XPath queries backed by parallel native search. Then export or convert to JSON, XML or CSV.

163× faster load

The result speaks for itself.

Approximate load time for a large JSON file. Where general-purpose editors stall or run out of memory, the structural index just opens.

OPENXMLJSON
0.4s
Notepad++
65s
VS Code
82s
Sublime
58s
Chrome
fails

Illustrative comparison of load performance on a large JSON file. Actual results vary by hardware, file shape and configuration.

Everything you need

A data workbench, not a text editor.

Browse and query your files like a database — with the tools you'd expect from an enterprise DBMS.

Virtualized tree view

Objects, arrays, XML elements and CSV records render in one uniform, collapsible tree. Cost per frame tracks visible rows (~40), never file size.

Regex find, instantly

Literal or regex search scoped to keys, values or attributes — chip-highlighted matches with stepping, backed by parallel native search.

JSONPath & XPath queries

Query JSON/CSV with $.store.items[*].name and XML with //item/@id. Combine paths with | to pull several fields at once; results filter the tree.

On-demand (lazy) indexing

Files too large to index eagerly open anyway — only the paths you expand are materialized, so resident memory tracks the subtree you view.

Follow tail (tail -f)

Follow a growing JSON / NDJSON / log file. Only newly appended lines are parsed each tick, so it stays cheap on huge, live files.

Convert & export

Export the whole document or any node as pretty JSON, XML or CSV — cross-format conversion built in, plus export of search matches.

Stop waiting on progress bars.

Download OPENXMLJSON and open your biggest file in seconds.

Windows · macOS · Linux · Essential edition available