Comparison

JS Shell vs HTML & Markdown Viewer

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

JS Shell

Features
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JS Shell is a pocket-sized developer console that lets you write, run, and test web code (HTML, CSS, JavaScript) directly on iOS and macOS. No Xcode, no laptop, no remote server. Paste a page in, tap run, and it loads in a real WKWebView served from a local HTTP origin. A real secure-context origin on iOS, so modern web APIs — from WebRTC to Geolocation — behave the way they should. KEY FEATURES Local HTTP server. An in-process server bound to the loopback interface. Provides a real secure-context origin so modern Web APIs work out of the box. Not reachable from outside the device. JavaScript REPL. A full JavaScript runtime backed by JavaScriptCore. Type js to enter the REPL. console.log, fetch, setTimeout, setInterval, Promises, and async await are all available. Real Promises, real microtasks, real JSON parsing, real URL parsing. Geolocation support. Test navigator.geolocation on a real iOS device. Permissions are handled by the system, just like Safari. Useful for validating location-based web features without deploying to a server. Persistent file system. Files you paste live in your Documents directory and survive app restarts. Each downloaded package gets its own directory. iCloud backup picks them up like any other app data. SQLite key-value store. A real B-tree on disk via SQLite. Read and write from your pages with same-origin fetch. No CORS configuration required. curl. A subset of curl built on URLSession. The flags X, H, d, i, I, o, A, m, v are supported. Pretty-prints JSON responses and saves binary blobs to the virtual filesystem. Archive extraction. In-process tar, tar.gz, tgz, gz, and zip extraction. No shelling out. Download a release tarball with curl, extract it, and run it immediately. Voice commands. Tap the mic, speak a command. Apple Speech framework converts speech to text. Auto-submits on detected silence. Voice commands are saved to the scripts list for one-tap re-run. Saved scripts. Save any sequence of commands as a named script. One-tap to re-run later. Voice-recognized commands are auto-saved to the scripts list for instant replay. Mac Catalyst support. Runs natively on macOS as a Mac Catalyst app. Multi-window, resizable, fullscreen-capable. The same code that runs on your iPhone runs on your Mac. DESIGNED FOR DEVELOPERS JS Shell is a tool for people who want to test web code on a real iOS device without installing Xcode, syncing files, or setting up a tunnel. It is especially useful for: Testing geolocation, camera, and microphone permission flows on iOS. Validating fetch, CORS, and cookie behavior on a real iPhone. Building small offline web tools that need persistent state. Running JavaScript snippets without opening Safari Inspector. Debugging mobile rendering edge cases on the device itself. PRIVACY JS Shell does not collect any user data. There is no telemetry, no ads, no analytics, no third-party SDKs, no remote configuration. Everything you type, paste, or download stays on your device. The local HTTP server only listens on the loopback interface and is not reachable from any network. The app forwards camera, microphone, speech recognition, and location permissions to web pages you load, exactly like Safari does on macOS. The first time a page tries to use them, iOS shows the standard system permission prompt. The first time a page tries to use them, iOS shows the standard system permission prompt.

About

HTML & Markdown Viewer

This app renders AI-generated HTML, Markdown, and ZIP files locally. It supports JavaScript, CSS, diagrams, and tables, offering PDF and PNG export. All processing occurs on-device for enhanced privacy.

Highlights
  • Local HTML rendering
  • Markdown viewing with Mermaid and tables
  • ZIP file extraction and browsing
  • PDF and PNG export
  • Private on-device processing
  • Import from various apps
Features
Read full description

Artifact Viewer opens AI-generated HTML, Markdown, and ZIP files — including JavaScript, CSS, Mermaid diagrams, and GFM tables — through a private local server for full compatibility. * AI Artifact Ready: Import from ChatGPT, Files, WeChat, Mail, and other apps. * Full Local Rendering: Everything runs on-device through a private HTTP server. * PDF & PNG Export: Export any view as PDF or the current screen as PNG. * ZIP Support: Extract and browse ZIP bundles with entry switching. * Markdown Viewer: Built-in template with Mermaid and table support. * Private by Design: All content stays in the app sandbox. Built for developers, researchers, and AI users who work with rich HTML artifacts.

Screenshots

JS Shell3 screens
HTML & Markdown Viewer4 screens

Verdict

The call

JS Shell and HTML & Markdown Viewer are too close to call on the numbers: across 5 compared parameters — price, ads, in-app purchases and device support among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ScorecardNo meaningful differences
JS Shell versus HTML & Markdown Viewer: the parameters behind the verdict, then further details
ParameterJS ShellHTML & Markdown Viewer
PriceFreeFree
Rating—4.0 (1 ratings) — better
Positive reviews—100.0% of reviews
Number of ratings—1 — better
AdsNoNo
In-app purchasesNoNo
Monetization—Free
DevicesiPhone, iPadiPhone, iPad
Requires iOS17.0 — better17.4
Further details — not scored
Size6 MB3 MB
Age rating17+4+
DeveloperJowb Inc.洪霞 刘

In-app purchases

None

JS Shell

No in-app purchases

None

HTML & Markdown Viewer

No in-app purchases

Questions

Is JS Shell free?
JS Shell is free to download, with no in-app purchases.
Is HTML & Markdown Viewer free?
HTML & Markdown Viewer is free to download, with no in-app purchases.
Do JS Shell or HTML & Markdown Viewer have ads?
Neither JS Shell nor HTML & Markdown Viewer shows ads.

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