A JSON viewer and analysis toolkit built for files that crash everything else
Native Rust + SIMD engine. Multi-GB JSON, HAR analysis, API client, SQL export — all offline, all on your Android device.
Made for developers, analysts, and engineers who need to inspect massive datasets directly on Android — no laptop required.
A native Rust core with SIMD acceleration handles what JavaScript-based viewers simply cannot. Tested with files over 100 GB.
Native code, not a JavaScript wrapper. SIMD acceleration for search and parsing on ARM64 devices.
First load builds a persistent index. Every subsequent open of even a multi-GB file is near-instant.
Streaming architecture designed to prevent Out-Of-Memory crashes on any Android device, regardless of file size.
Everything runs locally. No cloud uploads, no tracking servers, no account required. Your data never leaves your device.
Drop a .har file exported from Chrome DevTools, Firefox, or any proxy tool and get an
instant breakdown — request counts, timing waterfall, status distribution, error summary, and domain
analysis.
Total requests, transfer size, average response time, error count — at a glance.
DNS, connect, SSL, wait, and receive breakdown — visualized per request or as averages.
Headers, cookies, request body, response body with syntax highlighting, timing, TLS info.
Filter by method, status code, content type, domain, or response time. Full-text search across all requests.
Send any request from the HAR log directly to the built-in API client to replay, modify, and debug it.
An API development and testing environment built for mobile. Import Postman collections, configure environments, authenticate with OAuth 2.0 — and open every response directly in the JSON viewer. No pre-request or test scripts (no JS engine), but covers most real-world workflows.
GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS, and GraphQL queries with variable support.
Basic, Bearer Token, OAuth 2.0 with PKCE, AWS Signature V4. Tokens are stored and refreshed automatically.
Import existing Postman collections with full folder structure and environment variables. No Postman account needed.
Define environments with variable precedence. Switch between staging, production, or local with one tap.
Import any cURL command directly or export your request as cURL to share with teammates.
Detailed response timing, status code, headers, cookies, and body size — all in one place.
Multipart uploads, binary body payloads, and session cookie handling for complex workflows.
JSON responses open directly in the viewer — navigate, filter, search, and export the data immediately.
Each mode is purpose-built for a different workflow — not just different layouts of the same data.
An interactive hierarchical view for navigating deeply nested JSON structures. Stream through gigabytes like a feed. Supports JSON and NDJSON.
A bird's-eye view of your JSON schema — visualize the shape of unfamiliar data without reading it line by line. Supports JSON and NDJSON.
A high-performance raw text viewer for log analysis and deep search operations. Supports JSON, NDJSON, and plain text.
Go beyond reading — filter, query, and understand your data with purpose-built tools.
Build complex multi-condition filters without writing code. Combine field conditions using AND/OR logic with parentheses grouping — then export the results directly.
Describe in plain English what you want to find. The on-device AI generates the regex pattern — your data never leaves the device.
Convert any JSON dataset to database-ready SQL INSERT statements or flat CSV. Auto-detects column types with configurable dialects: MySQL, PostgreSQL, SQLite, SQL Server, Oracle, MariaDB.
A complete toolkit beyond just file viewing.
Transfer files from desktop to phone over WiFi. Drag and drop from your browser — no cables, no cloud, no desktop app needed.
Turn your phone into a mock API server. Define endpoints with custom methods, status codes, and response files. Includes a web dashboard with request logging.
Redact sensitive fields during export. Define which keys to mask before generating SQL or CSV output for safe sharing.
Render .md files with full markdown formatting. Useful for README files bundled with
data exports.
Validate JSON content against a schema file (JSON Schema Draft-07). Get instant pass/fail with error location details.
Fix stringified JSON (double-escaped backslashes) and beautify minified content in one tap — without opening the full viewer.
Save exact positions deep inside large files. Return to any bookmarked location instantly, even in multi-GB NDJSON streams.
Automatically identifies Base64-encoded values (40+ formats). Preview images inline, play audio/video, or extract the decoded file.
Developers use JWT decoders, timestamp converters, and JSON formatters every day. Most reach for online tools — fine, until you're working with production tokens, customer data, or anything behind an NDA.
GiantJSON hosts these tools locally on your phone. Open a browser on any device on the same network and use them. Nothing is sent to the internet. Ever.
Blocked corporate WiFi or strict firewall? Connect via USB tethering instead.
Transfer files between your desktop browser and phone. Drag and drop or use CLI commands.
Decode JWT tokens into header, payload, and signature. See algorithm, expiry status, and copy each part.
Convert between epoch timestamps and human-readable dates. Outputs seconds, milliseconds, UTC, local time, and ISO 8601.
Format, minify, stringify, or unescape JSON. Handles up to 1 MB of input.
Encode, decode, and parse URLs. Breaks down protocol, host, path, and query parameters.
All tools run entirely on your local network. No internet connection required.
Standard, minified, and large-value JSON files supported. NDJSON and JSONL for line-delimited datasets and event logs. CBOR and MessagePack binary formats are automatically transcoded to JSON on first open.
GiantJSON is a one-person project — built and maintained by a solo indie developer. It started as a tool to solve a problem no other app handled well, and evolved into a full developer toolkit.
If it's useful to you, a review on Google Play helps more than you'd think. And if something isn't working right, in-app feedback goes straight to me.