Comparison

JS Shell vs HTML Opener

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
Read full description

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 Opener

This app renders local HTML, CSS, and JavaScript files in a real browser on your iPhone and iPad. It allows you to open entire project folders, test responsive designs, and view web content as it would appear on a live website.

Highlights
  • Renders local HTML, CSS, JavaScript, and images
  • Opens entire project folders with relative paths
  • Desktop and mobile view toggle
  • Fullscreen mode for immersive viewing
  • Quick switcher for recent projects
  • Auto-launch primary tool on startup
Features
Read full description

When you open an HTML file in the iPhone Files app, iOS just dumps lines of raw code on your screen. Buttons do not work, styles break, and Safari cannot open local file links. HTML Opener fixes that. It runs your local HTML, CSS, JavaScript, and images in a real WebKit browser directly on your iPhone and iPad. No Mac, no terminal, and no local server required. WHAT IT SOLVES - Files app dumps raw code and text on screen instead of rendering the webpage - Safari has no address bar option to open local file:// links - Opening a single file breaks CSS styles and image assets in neighboring folders - Setting up a local server on your computer just to check mobile layout is tedious REAL WEBKIT BROWSER RENDERING Built on iOS's native WKWebView engine. Buttons, forms, CSS styling, canvas animations, and modern JavaScript run exactly as they would in Safari. OPEN AN ENTIRE PROJECT FOLDER Select a folder containing style.css, script.js, and an images directory alongside your HTML file. All relative file paths resolve automatically with zero broken images or missing styles. DESKTOP & MOBILE VIEW TOGGLE Switch between phone layout and 1024px desktop view with a single tap. Review horizontal dashboards, data tables, and desktop web tools without broken layouts. FULLSCREEN MODE Hide navigation bars and margins to give your web content the entire display. Web apps and tools feel like installed native apps. FOUR SIMPLE ACTIONS 1. Open a local file or folder 2. Quick Switcher to jump between recent projects 3. Auto-launch your primary tool as soon as the app starts 4. Clear cache, toggle dark theme, and customize display options WHO IT IS FOR - Anyone stuck when iPhone opens HTML as raw code - Developers and designers testing web prototypes on actual iOS hardware - Anyone running self-built dashboards, calculators, or tools on the go - Students learning web development who want instant mobile testing PRO (ONE-TIME PURCHASE, NEVER A SUBSCRIPTION) Removes ads completely. Pay once, use forever. Compatible with iPhone and iPad, iOS 17.0 or later. Stop dealing with raw code dumps. Open real interactive web pages with HTML Opener.

Screenshots

JS Shell3 screens
HTML Opener4 screens

Verdict

The call

The clearest difference is in-app purchases: JS Shell at none against HTML Opener's 1. JS Shell also leads on ads (none vs shown). On price, device support and iOS requirement there is nothing between them.

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. HTML Opener sells 1 one-off in-app purchase. JS Shell asks for nothing beyond the download.

Scorecard2 real differences · 7 level
JS Shell versus HTML Opener: the parameters behind the verdict, then further details
ParameterJS ShellHTML Opener
PriceFreeFree
Rating—5.0 (2 ratings) — better
Number of ratings—2 — better
Update frequency—Every 4 days
AdsNo — betterYes
In-app purchasesNo — betterYes
Monetization—Free with in-app purchases
DevicesiPhone, iPadiPhone, iPad
Requires iOS17.017.0
Further details — not scored
Size6 MB12 MB
Age rating17+4+
DeveloperJowb Inc.GASHIMA LAB

In-app purchases

None

JS Shell

No in-app purchases

1 purchases

HTML Opener

One-time1
  • HTML Opener PRO$4.99

Questions

Is JS Shell free?
JS Shell is free to download, with no in-app purchases.
Is HTML Opener free?
HTML Opener is free to download, with in-app purchases available.
Do JS Shell or HTML Opener have ads?
HTML Opener shows ads; JS Shell does not.

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