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NDJSON Field Filter
Select, drop or rename top-level NDJSON fields while preserving exact numeric tokens and record order.
Pasted strict NDJSON, One UTF-8 NDJSON/JSONL/text file
filtered.ndjson, field-filter-report.json
Browser only
Runs locally in your browser. Your files, pasted content and generated output are not uploaded. Reset clears this tool’s working data.
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How to use this tool
- Enter the admitted input using NDJSON input, Field operation, Fields (JSON array), Renames (JSON object), Missing field. A selected UTF-8 source file takes precedence over paste.
- Choose select, drop or rename. Fields is a JSON array for select/drop; Renames is a simultaneous JSON object mapping for rename. Set the missing-field policy.
- Select Edit NDJSON fields and download filtered.ndjson, field-filter-report.json.
Examples
Selecting ["id"] keeps the id member of every object; a simultaneous a-to-b and b-to-a rename swaps those names without sequential overwrite.
Limitations
- 5 MiB source; 50,000 records, 1 MiB per record, depth40 and200,000 cumulative source values. Selected configuration up to64 KiB,500 names/maps,1,000 UTF-16 units per name and1,001 configuration values.
- One optional initial BOM, LF/CRLF frames and terminal LF for a nonempty stream. No blank record, bare CR, unexpected BOM, duplicate member or nonobject record. Empty/BOM-only input is valid.
- Combined artifacts20 MiB;30-second processing limit. Exact top-level names only: no paths, wildcards, regex, coercion or partial valid-record output. Rename collisions reject even for equal values.
- Report field counts measure present selections, actual drops or present nonidentity renames. Affected records have a changed key order/set or a performed nonidentity rename; the counter does not measure serialized-byte differences.
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