jsonl-viewer: view and edit JSONL fine-tuning datasets
Melvin Vivas · X post · 2026-08-16 · Open on X
Topics: Fine-tuning & Model Customization, AI Dev Tools & Productivity · Level: beginner
Summary
The creator added a file explorer to jsonl-viewer, his open-source tool for viewing and editing .jsonl files. These files are often used for fine-tuning and training datasets, so the tool helps when you inspect or clean training data.
Key points
- JSONL (one JSON object per line) is the usual format for fine-tuning and training datasets
- jsonl-viewer lets you view and edit .jsonl files
- The new file explorer lets you browse and open several dataset files
Resources mentioned
- donvito/jsonl-viewer · repo · github.com · free
Open-source tool for viewing and editing .jsonl files (fine-tuning datasets) and agent traces from Codex, Claude Code, Pi and Hermes.
Also in: jsonl-viewer: Live Traces for Codex Orchestrator and Subagents (Melvin Vivas on X · notes), See live Codex traces with the jsonl-viewer tool (Melvin Vivas on X · notes), Melvin Vivas's open-source AI tools, built with Codex (Melvin Vivas on X · notes), Analyzing Codex Traces with jsonl-viewer (Melvin Vivas on X · notes) and 12 more
Try this
- Try jsonl-viewer to inspect and edit your fine-tuning datasets
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