Large files

Open and scroll multi-gigabyte JSON with no lag.

Most JSON tools choke the moment a file gets big — they read the whole thing into memory and parse it up front. Pandia does not. It opens hundreds of megabytes, or several gigabytes, instantly, and scrolling stays smooth the whole way down.

How it stays fast

At 10 MB and above, a document switches to lazy, zero-copy slicing (powered by sonic-rs). Instead of parsing the entire tree, Pandia only loads the slice currently on screen. Opening, scrolling, and expanding never parse the whole document, so a 3 GB file feels the same as a 30 KB one.

There is no cap on opening or viewing. Whatever the size, you can open the file and browse it.

Note — don't confuse the lazy threshold with a limit. The 10 MB mark is where Pandia starts slicing for speed — it is not a ceiling. Opening and viewing remain uncapped at any size.

The 200 MB ceiling

Whole-document operations are capped at 200 MB. A few actions need the entire document materialized at once — full edit, export, and schema-validation. These are limited to documents of 200 MB or less. Opening and browsing a larger file still works; only those whole-document operations are unavailable above the ceiling.

Type generation is an exception: it infers types by streaming over the lazy document, so it works at any size — the 200 MB ceiling only applies when generating a JSON Schema, which materializes the whole document.

Other limits

Two views have their own thresholds, for the same reason — they materialize content rather than slicing it:

FeatureLimit
Code-view editor50 MB
Inline diff3 MB per side

The Tree, Grid and Graph views keep working on much larger documents because they read from the lazy slice, not the whole tree.

Next steps

Hitting one of these limits? See Troubleshooting. To pick a comfortable density and font for long sessions, see Themes & appearance.