Jsonl Viewer – An offline JSON Lines viewer in a single HTML file

Name: Jsonl Viewer – An offline JSON Lines viewer in a single HTML file
Availability: InStock
Author: Cassandra99

by Cassandra99·Apr 9, 2026·3 points·2 comments

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AI Analysis

●●SolidCozySolve My Problem

Single HTML file that auto-expands nested tool-call args better than JSONLint.

Strengths

•Zero dependencies — single HTML file works offline with no server required
•Auto-expands nested JSON strings specifically for tool-call argument inspection
•Toggle renders \n as actual line breaks for reading embedded markdown and code

Weaknesses

•Narrow scope — only handles JSONL, not other log formats or streaming data
•Basic JSONL viewing already exists in VS Code extensions and online tools

Post Description

I build AI agents and got tired of squinting at raw JSONL chat logs. Existing online viewers either choke on JSONL or upload your data. So I made one that runs offline in a single HTML file. Paste JSONL → auto-formatted with syntax highlighting. Auto-expands nested JSON strings (common in tool-call args). Toggle to render \n as real line breaks for reading embedded markdown/code. It's just one HTML file — open DevTools to inspect, Ctrl+S to save your own copy and modify however you like. https://tasks.hamsterbase.com/jsonl-viewer/