Jeyso vs JSON Viewer
Price, ratings, monetisation and update history for both apps, side by side β with what reviewers say about each.
Jeyso
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Master the art of data engineering with Jeyso, the premium JSON formatting studio designed for absolute focus and technical excellence. Whether you're debugging a complex API response or optimizing your data structures, Jeyso provides a sophisticated platform to manage your JSON through a high-fidelity, intuitive interface. With advanced formatting modules and an intelligent validation framework, Jeyso eliminates the noise of cluttered developer apps. Experience a refined way to stay organized, featuring immersive history logs and high-fidelity project management that celebrates your technical achievements in a secure and professional environment. KEY HIGHLIGHTS: β’ Advanced JSON Formatting: Master your data with high-fidelity support for large JSON structures of up to 1,000,000 characters with absolute precision. β’ Comprehensive Validation Studio: Validate and optimize your JSON through a streamlined, intuitive dashboard with customizable indentation controls. β’ Intelligent History Framework: Monitor your data journey and revisit your projects with a high-fidelity log of up to 100 entries and 30-day retention. β’ Mindful Developer Experience: A sleek, professional design optimized to reduce cognitive load and foster deep technical focus. β’ Secure Data Registry: Document your JSON history and revisit your favorite structures with a high-fidelity history system. β’ Privacy First: Your data is personal. Jeyso processes all your JSON locally on your deviceβwe never access or share your private technical records. WHY JEYSO? Most JSON tools feel generic and cluttered. Jeyso is designed with care β smooth animations, high-fidelity technical interactions, a refined design system, and a formatting framework that's actually robust. It's the developer companion you'll keep coming back to.
JSON Viewer
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Paste a JSON blob β an API response, a config file, a log payload β and JSONView turns it into a collapsible, colour-coded tree the moment it lands. Validate it with an error that names the exact line and column, format or minify it, and copy it back out. Everything happens on your iPhone, offline, so your payload never touches a web tool. Most JSON apps wrap the same lenient system parser. JSONView ships its own strict RFC 8259 engine: it preserves your key order instead of scrambling it, keeps number literals exactly as written, rejects the trailing commas other parsers silently swallow, and warns you about duplicate keys β with the position of both copies. WHAT YOU GET β’ Paste an API response and read it as a collapsible tree in under a second, with keys, strings, numbers and booleans each in their own colour β’ Broken JSON tells you exactly where: "Line 14, column 27 β trailing comma before '}'" instead of a shrug β’ Duplicate keys are flagged with both positions, so the bug that only bites in production gets caught on your phone β’ Find any key or value in a deep payload and jump to it with its full $.path[3].to.node β’ One tap copies a value, its path, or the whole document β pretty-printed or minified β to the clipboard β’ Round-tripping never rewrites your data: key order survives, 1e3 stays 1e3, -0 stays -0 PERFECT FOR β’ Backend and mobile developers checking an API response away from the desk β’ QA engineers pinning down exactly which field broke the build β’ Support and ops engineers reading the log payloads customers send in β’ Anyone learning what valid JSON actually is, from a parser that explains every rejection WHY NOT JUST A WEB FORMATTER? Every browser JSON tool means pasting your payload β auth tokens, emails, customer records β into someone else's server. JSONView parses entirely on-device and works in airplane mode. It also opens .json files straight from Files, Mail or Slack, so you skip the copy-paste dance entirely. PRIVATE BY DEFAULT No network calls. No account. Your documents are parsed and stored only on your iPhone, and your saved library never leaves the device. FULL ACCESS JSONView Pro unlocks the complete toolkit: an unlimited saved-document library, minify to clipboard, .json file export, custom indent width, and A-to-Z key sorting. Choose a weekly plan, a yearly plan, or a one-time lifetime purchase. Weekly and yearly plans are auto-renewing subscriptions; lifetime is a single payment. Copy a JSON payload, open JSONView, and tap Paste β the tree is already waiting. Terms of Use: https://leanstudio.asia/terms-of-use Privacy Policy: https://leanstudio.asia/privacy-policy Support: support@leanstudio.asia
Screenshots
Verdict
The clearest difference is update cadence: Jeyso at monthly against JSON Viewer's every 4 months. On price, ads, in-app purchases and device support there is nothing between them.
Scored on Price Β· Rating Β· Positive reviews Β· Number of ratings Β· Update frequency Β· Ads Β· In-app purchases Β· Monetization Β· Best chart rank Β· Devices Β· Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
Jeyso ships an update monthly, JSON Viewer every 4 months. The most recent releases landed on September 26, 2026 and September 21, 2026 respectively.
| Parameter | Jeyso | JSON Viewer |
|---|---|---|
| Price | Free | Free |
| Update frequency | Monthly β better | Every 4 months |
| Ads | No | No |
| In-app purchases | No | No |
| Devices | iPhone, iPad β better | iPhone |
| Requires iOS | 17.0 | 17.0 |
| Further details β not scored | ||
| Size | 5 MB | 4 MB |
| Age rating | 4+ | 4+ |
| Developer | Umit UZ | LEAN ASIA CO., LTD |
In-app purchases
Jeyso
No in-app purchases
JSON Viewer
No in-app purchases





