JupyLens - Jupyter Notebook Viewer & Editor

Name: JupyLens - Jupyter Notebook Viewer & Editor
Author: niloy

By: niloy

Open, render, and edit Jupyter Notebook (.ipynb) files directly in the browser with 13 themes. Does not execute or run notebook code.

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Install

Features & Capabilities

JupyLens opens, renders, and edits Jupyter Notebook (.ipynb) files directly in your browser. No Jupyter server, no Python installation, no setup — just open your notebook and start reading or editing.

Important: This add-on does not execute or run notebook code. It is a viewer and editor only — you can read and edit cell source text, but code cells are never executed.

Key Features

Instant Rendering: Open any .ipynb file and see it rendered with formatted markdown, syntax-highlighted Python code, and all cell outputs, including images, HTML tables, and error tracebacks.
Auto-Open: Navigate to any .ipynb file URL (local or remote) and JupyLens automatically intercepts and renders it.
13 Themes: Choose from GitHub Theme, One Dark Pro, Dracula, Monokai Pro, Tokyo Night, Ayu, One Monokai, Rose Pine, Shades of Purple, Winter Is Coming, Solarized Light, Solarized Dark, and Nord. Your selection is saved across sessions.
System-Aware Defaults: Automatically selects Ayu for dark system themes and GitHub Theme for light system themes on first launch.
Inline Editing: Click the Edit button on any cell to modify its source. Tab key inserts 4 spaces. Save commits the change; Cancel discards it. Download the modified notebook as an .ipynb file.
Line Numbers: Toggle line numbers on code cells with one click. The preference is saved automatically.
Rich Output Support: Displays stream output, execution results, display_data with base64-encoded PNG/JPEG/GIF images, inline SVG, HTML content, and error tracebacks with full ANSI color rendering (including 256-color codes).
Drag and Drop: Drop a notebook file onto the viewer to open it instantly.

Privacy

JupyLens processes all notebook files entirely within your browser. No data is uploaded, transmitted, or shared with any server. The add-on stores only your theme preference and line number setting using browser.storage.local. No analytics, tracking, or third-party services are used. The add-on works completely offline.

Technical Details

Manifest V2 compliant
Zero external dependencies — no npm packages, no CDN scripts, no build step
Built-in markdown parser, Python syntax highlighter, and ANSI escape code parser
All JavaScript is bundled locally within the add-on package

Support

Report issues or contribute at: https://github.com/sajjad-ahmed/jupylens

Developed by Sajjad Ahmed Niloy.

User Growth & Download Statistics

Add-on

By:

niloy

Daily users:

Version:

1.2.0 Last updated: 2026-04-07

Version code:

6208594

Creation date:

2026-04-04

Risk:

Permissions:

storage

Content scripts matches:

<all_urls>

Size:

91.46KB

URLs:

Website

Full description:

Source:

Firefox Add-ons Store

Data ingested on:

2026-06-14

Compare stats and ranking:

Ranking

# 44,453 ▼ 368

Other rankings

#23 in notebook keyword 32 ▼ 1#138 in editor keyword 26 ▼ 1#229 in text editor keyword 18 ▼ 1#236 in css editor keyword 28 ▲ 2

For Developers

Monetize with App Pass Boost with Extension Booster

Contact the developer

Chrome-Stats does not own this Firefox add-on. Please use these information below to contact the Firefox add-on developer.

Developed by:

niloy

Firefox Add-ons Store

https://addons.mozilla.org/firefox/addon/jupylens/

Website:

https://niloy.red/

Is JupyLens - Jupyter Notebook Viewer & Editor Safe?

Risk impact

Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.

JupyLens - Jupyter Notebook Viewer & Editor requires a few sensitive permissions. Exercise caution before installing.

Risk impact analysis details

Critical Allows access to all websites, posing a significant security risk as it can monitor and modify data from any visited site.
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Risk likelihood

Risk likelihood measures the probability that a Firefox add-on may turn malicious. This is determined by the publisher and the Firefox add-on reputation on Firefox Add-ons Store, the amount of time the Firefox add-on has been around, and other signals about the Firefox add-on. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Firefox add-on.

JupyLens - Jupyter Notebook Viewer & Editor is recently added, and hasn't been around long enough for us to gather enough data to accurately assess its risk level.

Risk likelihood analysis details

High This extension has low user count. Unpopular extensions may not be stable or safe.
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