How to Export JSON Differences Beyond the 300-Result View

The 300-result limit in JSON Mirror applies to the visible list, not to the exported report. After a successful comparison, Export report downloads the complete changes array. Choose the right original and updated documents, compare them again after any edit, and use the JSON file when you need every recorded difference.

Open JSON Mirror

The visible list and the report serve different purposes

JSON Mirror keeps the comparison result in memory as a changes array. Its screen renderer selects the current filter and draws only the first 300 matching entries. If more matches exist, a notice explains that the list is shortened and directs you to export the report. That notice describes a display boundary; it does not mean that comparison stopped after finding 300 differences.

For example, a comparison with 305 added values can display 300 cards while the downloaded report still contains all 305 changes. Use the filters to inspect particular kinds of differences, and use the export when a later review needs the full recorded set. The app does not currently offer pagination through every result card.

Compare the intended inputs before exporting

Put the earlier document in Original and the later document in Updated, then select Compare JSON. The direction matters because the result describes additions and removals relative to those two inputs. If you swap them, compare again before exporting. The report should represent the comparison you actually intend to share or inspect.

Editing either input after a comparison makes the displayed result stale. JSON Mirror disables the export control and asks you to compare again. Do not treat an older visible list as evidence that your latest edits were compared. Complete another successful comparison first; validation or comparison errors also leave exporting disabled.

Know what the downloaded file contains

Export report creates a JSON download named json-mirror-report.json. Its top-level data identifies the tool, records that array comparison is by index, and includes the in-memory report with a comparison timestamp and changes. The export handler uses that report directly rather than exporting just the currently selected screen filter.

This distinction matters when you inspect only Added or Removed on screen. A filter helps you browse the comparison, but it does not turn the downloaded file into a filtered report. If another workflow requires only one change kind, inspect the downloaded changes array and select the relevant records in that workflow. JSON Mirror does not provide that separate export option.

Understand the limits an export does not remove

A complete export means the complete result of a successful comparison, not unlimited input support. Each editor has a one-million-character input limit. Comparisons may also fail when the supported nesting depth is exceeded. Exporting cannot bypass those checks or recover a comparison that never completed.

The arrayComparison field is a reminder of another boundary: arrays are compared by index. A moved or inserted item can therefore produce several position-based differences. The downloaded file preserves that interpretation; it does not independently detect moves or match objects by an identity field. Read those changes in the context of your data.

Keep a report only when your workflow needs it

The app builds the download from a browser Blob when you choose Export report. This lets you decide when to create a file instead of treating every comparison as something to retain. Once you download or share the report, handle it according to the sensitivity of the values it contains. A local tool does not make a shared output harmless.

For a repeatable review, confirm the input direction, run a fresh successful comparison, note any shortened-list notice, and download the report. Check that the changes array is the result you expected before passing the file onward. The comparedAt timestamp records when that comparison was made; it is not proof that the source documents are current.

AI-assisted ForgeHub editorial. App capabilities were checked against its implementation; this guide is not an independent review.