About ViewJSON
ViewJSON is a free online JSON viewer and formatter built for developers who work with APIs that return Base64-encoded media. Unlike traditional JSON formatters that treat every string value as plain text, ViewJSON automatically detects Base64-encoded content and renders it as actual images, audio players, video players, or PDF previews — directly inside the JSON structure. All processing happens locally in your browser — your data never leaves your device.
Why We Built This
Multimodal AI APIs — OCR, TTS, vision models, image generation — exchange data almost entirely in Base64. During development and testing, this creates several recurring pain points:
Tedious output preview
TTS and image generation APIs return Base64-encoded audio and images. Previewing them requires extracting the string from a JSON response, pasting it into an online decoder, and repeating the process for every field.
Error-prone input construction
Calling OCR or vision models requires converting images to Base64 on a third-party website, then pasting the string into the request body of your API tool. The process is fragile — a misplaced quote or broken escape sequence means time spent fixing JSON syntax rather than debugging your actual logic.
Inconvenient history review
Postman and Fiddler save your request history, but Base64 fields appear as long encoded strings with no indication of the actual content. Reviewing what was sent or received requires extracting each Base64 string and decoding it separately.
So we built ViewJSON: paste your JSON and immediately see every image, hear every audio clip, and play every video — without leaving the page.
Use Cases
Debugging AI API Responses
Paste an API response containing Base64-encoded media into ViewJSON. All audio clips, images, and videos are automatically detected and rendered inline within the JSON structure — no manual extraction or external decoders needed.
Preparing Multimodal API Payloads
Paste an image directly into the editor. ViewJSON displays the image preview while storing the Base64 string in the JSON. When you copy, you get a ready-to-use Base64 payload — no separate file-to-Base64 conversion needed.
Sharing JSON with Your Team
ViewJSON compresses your JSON with pako (zlib) and encodes it into a shareable URL. No file uploads, no cloud storage, no expiring links. The recipient opens the link and sees the formatted data with full media preview — all decoded client-side.
Tech & Privacy
Built with Astro + React
Islands architecture for minimal JavaScript. Only interactive components load client-side code.
CodeMirror 6 Editor
Professional-grade code editor with syntax highlighting, folding, search, and bracket matching. Handles files over 10 MB without performance issues.
Cloudflare Pages
Deployed globally on Cloudflare's edge network for fast load times worldwide.
Data Privacy
Your JSON is processed entirely in your browser and never sent to any server — even the sharing feature encodes data into the URL itself.
Contact
Questions, feedback, or feature requests? Reach us at support@viewjson.net