OnlineUtils
Markdown
Write GitHub-flavored Markdown with a side-by-side preview. Supports HTML, typographic replacements, and one-key formatting via Prettier.
JSON Viewer
Format, validate, and browse JSON in an interactive tree with syntax highlighting. Sort keys and auto-decode nested JSON strings. Nothing leaves the browser.
SVG Optimize
Compress SVG files with the full SVGO plugin chain. Remove metadata, minify paths, and cut file size by up to 80%. Live preview and PNG export in the browser.
Diff
Compare two text blocks or JSON objects side by side with line, word, and character granularity. Sort JSON keys before diffing to ignore reorderings.
QR Code
Generate QR codes for text, URLs, and WiFi credentials. Customize colors, dot patterns, corner shapes, and add a logo. Download as PNG, SVG, JPEG, or WebP.
Encoder / Decoder
Convert between Base64, URL encoding, HTML entities, Unicode escapes, and Hex. Decode JWT tokens. Add multiple panels to compare encodings side by side.
Share
Share a text snippet by short link and QR code. Open on any device, or scan the QR from your phone. Same link can be updated later. 10 KB per snippet.
HTML Viewer
Type or paste HTML on the left and see the rendered output on the right. Monaco editor with syntax highlighting. Scripts run in a sandboxed iframe.
Config Converter
Convert config between JSON, JSONC, YAML, TOML, XML, and INI in any direction. Input format is auto-detected. JSONC output preserves comments.
Voice Sample
Record a voice sample in the browser, drag to crop the range, and download as 16-bit PCM WAV. Suits voice cloning and podcast intros. AGC is disabled.
Image Compress
Compress PNG, JPEG, and WebP in the browser using MozJPEG, OxiPNG, and libwebp via WebAssembly. Batch up to 20 files, format is preserved.
Prompt Viewer
Paste an escaped one-line string with \n, \t, \", \uXXXX and see it unescaped side by side. Optional Markdown rendering. Suits AI system prompts and log lines.