AI Dataset Deduplicator

Remove exact and near-duplicate rows from fine-tuning datasets.

Works Offline
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No Login
No API
Records in
4
Unique kept
2
Duplicates removed
2
Invalid lines
0

Input JSONL

Drop a file here

or choose a file — it never leaves your device

Deduplicated JSONL

Removed records — 2

  • Line 2Duplicate after normalisation: {"prompt":"what is rag?","completion":"Retrieval augmented generation."}
  • Line 3Duplicate after normalisation: {"prompt":"What is RAG?","completion":"Retrieval augmented generation."}

About the AI Dataset Deduplicator

Load a JSONL dataset and strip duplicates by exact text, case and whitespace insensitive match, or fuzzy near-duplicate detection using word shingles with an adjustable similarity threshold. Compare on any field or the whole record, and export the cleaned file.

Examples

Dedupe prompts

4 rows, 2 duplicate prompts

Output

3 unique rows kept

Keyboard shortcuts

  • Copy the main outputCtrl / ⌘ + Shift + C
  • Download the resultCtrl / ⌘ + S
  • Share this toolCtrl / ⌘ + Shift + S
  • Reset the inputsAlt + R
  • Open the tool search paletteCtrl / ⌘ + K

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Frequently asked questions

Version 1.0.0 · Updated 2026-08-15 · Runs entirely in your browser