Make tools simple and pure

Validate Apple App Site Association (AASA): check reachability, Content-Type, JSON structure and applinks rules; includes a Universal Links matcher and a troubleshooting guide.

Free online AES-256 Encrypt / Decrypt. Runs locally in your browser with zero uploads for privacy and speed.

Free online API key generator with multiple key formats, secure high-strength random generation, all processing completed locally in browser.

Free online API Tester. Runs locally in your browser with zero uploads for privacy and speed.

Free online audio auto silence trimmer: Based on ffmpeg.wasm silenceremove, supports threshold/duration adjustment and WAV/MP3 export.

Free online Audio Encoder. Runs locally in your browser with zero uploads for privacy and speed.

Free online audio format converter (MP3/WAV/FLAC/OGG/M4A/OPUS) with bitrate/sample-rate/channels and basic metadata. Runs locally.

Free online Audio Merger. Runs locally in your browser with zero uploads for privacy and speed.

Free online audio noise reduction tool with FFmpeg-based processing, support for WAV/MP3 formats, real-time preview.

Free online Audio Trimmer. Runs locally in your browser with zero uploads for privacy and speed.

Free online audio video metadata viewer: Parse container, duration, bitrate, resolution, audio sample rate and other information, supports copying JSON, pure frontend local processing.

Free online AV Transcoder. Runs locally in your browser with zero uploads for privacy and speed.

Free online Base Converter. Runs locally in your browser with zero uploads for privacy and speed.

Free online Base32 / Base58 Converter. Runs locally in your browser with zero uploads for privacy and speed.

Free online Base64. Runs locally in your browser with zero uploads for privacy and speed.

Free online Bcrypt/Argon2id hash generation and verification tool: locally compute encoded hash, support verification, no password upload.

Free online bulk QR code generator. Generate many QR PNGs and download as a ZIP. Runs locally.

Free online Calculator. Runs locally in your browser with zero uploads for privacy and speed.

Free online Camera. Runs locally in your browser with zero uploads for privacy and speed.

Free online case converter for text: lower/upper/sentence/title/camel/snake/kebab and more. Runs locally in your browser with zero uploads for privacy.

Free online citation formatter for APA 7, MLA 9, Chicago, IEEE, and GB/T 7714. Fill in authors/title/journal or website info and copy the result. Runs locally.

Free online color contrast checker for WCAG 2.1 AA/AAA with pass/fail results, suggestions, and simple color-blind simulation. Runs locally.

Free online Color Converter. Runs locally in your browser with zero uploads for privacy and speed.

Upload an image and extract dominant colors as HEX values and ready-to-use CSS variables, processed fully in your browser.

Free online Color Picker. Runs locally in your browser with zero uploads for privacy and speed.

Free online Compass. Runs locally in your browser with zero uploads for privacy and speed.

Free online contract multi-version comparison: Using baseline text as reference, compare multiple versions line-by-line and highlight additions/deletions, supports copying unified diff.

Free online CORS checker: enter URL, method, headers and body to predict preflight and get common fixes for CORS errors.

Free online Cron expression generator with presets, validation, and next-run preview. Runs locally in your browser.

Free online Cron Expression Parser. Runs locally in your browser with zero uploads for privacy and speed.

Free online Content Security Policy generator with security analysis, real-time preview, and validation features.

Free online CSR generator with Apple Developer CSR mode (email + common name) and an advanced mode for RSA/EC PKCS#10 CSRs with SAN/KeyUsage/EKU options.

Free online CSS gradient generator: Create linear and radial gradients, add color stops, preview results, copy CSS code.

Free online CSV ↔ Excel Converter. Runs locally in your browser with zero uploads for privacy and speed.

Free online CSV to JSON Converter. Runs locally in your browser with zero uploads for privacy and speed.

Free online CSV to YAML Converter. Runs locally in your browser with zero uploads for privacy and speed.

Free online CSV data visualization tool with table preview, statistics, and simple charts.

Free online cURL to Code. Runs locally in your browser with zero uploads for privacy and speed.

Extract titles and URLs from resource text, or map links to platform codes locally in your browser.

Free online DES. Runs locally in your browser with zero uploads for privacy and speed.

Free online DOCX viewer and DOCX to PDF tool. Render .docx locally in your browser and export via print/save as PDF. No uploads.

Free online emoji picker with category browsing, search, one-click copy, and recent usage history, all processing completed locally in browser.

Free online Escape / Unescape Tool. Runs locally in your browser with zero uploads for privacy and speed.

Library of common Excel formulas with syntax, examples, and a simple interactive picker.

Free online Excel merger: merge multiple .xlsx/.xls into one workbook, keep sheets or merge into a single sheet. Runs locally.

Free online Excel to JSON. Runs locally in your browser with zero uploads for privacy and speed.

Free online file encrypt decrypt tool: AES-256-GCM + PBKDF2, locally encrypt any file and output savable encrypted JSON.

Free online metadata removal tool: Clean EXIF and other metadata from images through re-encoding, clear common document information fields from PDF through resaving.

Free online full page/long screenshot for any webpage (requires Fireoa Tools Chrome extension). Runs locally in your browser.

Free online GIF Optimizer. Runs locally in your browser with zero uploads for privacy and speed.

Free online GIF to Video Converter. Runs locally in your browser with zero uploads for privacy and speed.

Free online Go map <-> JSON converter. Convert Go map fmt output to JSON and convert JSON back to Go map. Runs locally in your browser.

Free online Gzip / Deflate Tool. Runs locally in your browser with zero uploads for privacy and speed.

Free online Hash Tools. Runs locally in your browser with zero uploads for privacy and speed.

Free online HMAC Generator. Runs locally in your browser with zero uploads for privacy and speed.

Free online HTML Stripper. Runs locally in your browser with zero uploads for privacy and speed.

Free online HTML to Markdown converter: paste HTML and convert to Markdown locally in your browser. Supports GFM tables/task lists.

Free online HTTP Header Parser. Runs locally in your browser with zero uploads for privacy and speed.

Free online ICNS Generator. Runs locally in your browser with zero uploads for privacy and speed.

Free online ICO Generator. Runs locally in your browser with zero uploads for privacy and speed.

Free online icon font converter: Convert WOFF2/WOFF/TTF/OTF/EOT to Base64 Data URL and generate @font-face CSS.

Free online ID photo processor: presets, custom size, background color, zoom/position, export PNG/JPG. Runs locally.

Compress, crop, and resize images locally in your browser. Export JPG, PNG, or WebP with quality controls and preview before downloading.

Free online Image Compressor. Runs locally in your browser with zero uploads for privacy and speed.

Free online Image Converter. Runs locally in your browser with zero uploads for privacy and speed.

Free online Image Cropper. Runs locally in your browser with zero uploads for privacy and speed.

Free online Image Resizer. Runs locally in your browser with zero uploads for privacy and speed.

Free online image to PDF converter: Supports multi-image merging, sorting, A4/Letter/custom sizes, DPI and margin settings, pure frontend local generation.

Free online image upscaler with 2×/3× enlargement. Uses RealCUGAN (WASM local CPU) when available, otherwise falls back to high-quality resize.

Free online INI/YAML/JSON converter with basic validation and copy output. Runs locally in your browser.

Free online JSON ↔ YAML Converter. Runs locally in your browser with zero uploads for privacy and speed.

Free online JSON Compare. Runs locally in your browser with zero uploads for privacy and speed.

Free online JSON diff visual comparison: Recursively compare object/array structures, tree-view display of additions/deletions/changes/type changes.

Free online JSON Formatter. Runs locally in your browser with zero uploads for privacy and speed.

Free online JSON Schema Validator. Runs locally in your browser with zero uploads for privacy and speed.

Free online JSON to C# Class. Runs locally in your browser with zero uploads for privacy and speed.

Free online JSON to CSV. Runs locally in your browser with zero uploads for privacy and speed.

Free online JSON to Excel. Runs locally in your browser with zero uploads for privacy and speed.

Free online JSON to Go Struct. Runs locally in your browser with zero uploads for privacy and speed.

Free online JSON to Java POJO. Runs locally in your browser with zero uploads for privacy and speed.

Free online JSON to JSON Schema. Runs locally in your browser with zero uploads for privacy and speed.

Free online JSON to Kotlin Data Class. Runs locally in your browser with zero uploads for privacy and speed.

Free online JSON to Python Model. Runs locally in your browser with zero uploads for privacy and speed.

Free online JSON to Rust Serde Struct. Runs locally in your browser with zero uploads for privacy and speed.

Free online JSON to TypeScript. Runs locally in your browser with zero uploads for privacy and speed.

Free online JWT Decoder. Runs locally in your browser with zero uploads for privacy and speed.

Free online JWT Generator. Runs locally in your browser with zero uploads for privacy and speed.

Lightweight Markdown editor with live preview, built for quick notes and documentation.

Free online Markdown to Confluence format converter with real-time preview and one-click copy, all processing completed locally in browser.

Free online Markdown to PDF Converter. Runs locally in your browser with zero uploads for privacy and speed.

Free online Markdown to Word content format converter with rich text format preservation and one-click copy to Word documents, all processing completed locally in browser.

Free online Music Player. Runs locally in your browser with zero uploads for privacy and speed.

Free online Noise Meter. Runs locally in your browser with zero uploads for privacy and speed.

Free online P2P File Transfer. Runs locally in your browser with zero uploads for privacy and speed.

Free online Palette Generator. Runs locally in your browser with zero uploads for privacy and speed.

Free online password strength checker that evaluates password complexity and can query known breach records with k-anonymity, without uploading the full password.

Free online PDF Compressor. Runs locally in your browser with zero uploads for privacy and speed.

Free online PDF Crop / Trim. Runs locally in your browser with zero uploads for privacy and speed.

Free online PDF encrypt decrypt tool: Use AES-256-GCM to encrypt PDF files to JSON, and decrypt to restore original PDF (pure frontend local processing).

Free online PDF Merger. Runs locally in your browser with zero uploads for privacy and speed.

Free online PDF page extractor. Extract selected page ranges to a new PDF or export per-page PDFs as a ZIP.

Free online PDF page merger & reorder. Merge multiple PDFs, reorder files, and select page ranges per file locally.

Free online PDF page rotator. Rotate all pages or selected pages (90/180/270) locally in your browser.

Split PDFs or extract selected pages locally in your browser, exporting PDF or ZIP (no uploads).

Free online PDF Stamp / Watermark. Runs locally in your browser with zero uploads for privacy and speed.

Free online PDF TOC generator: Enter page numbers and titles, automatically generate table of contents page and insert into PDF (pure frontend local processing).

Convert PDF pages to PNG/JPG images locally and download as a ZIP (no uploads).

Extract text from PDF locally in your browser and export as TXT or ZIP (no uploads).

Convert PEM/DER/JWK/JWKS locally in your browser and inspect key fields (no uploads).

Free online PPT Compressor. Runs locally in your browser with zero uploads for privacy and speed.

Free online Protractor. Runs locally in your browser with zero uploads for privacy and speed.

Free online QR Code Generator. Runs locally in your browser with zero uploads for privacy and speed.

Free online QR Decoder. Runs locally in your browser with zero uploads for privacy and speed.

Free online QR Scanner. Runs locally in your browser with zero uploads for privacy and speed.

Free online Random Number Generator. Runs locally in your browser with zero uploads for privacy and speed.

Free online random password generator: configure length, character sets, excluded characters, and quantity. Saves generated passwords to local history (password + time).

Free online Regex Tester. Runs locally in your browser with zero uploads for privacy and speed.

Validate and run regular expressions locally in your browser with presets, global matching, ignore-case mode, replacement preview, saved custom rules, and copyable results.

Free online RSA Key Generator. Runs locally in your browser with zero uploads for privacy and speed.

Free online Salt Generator. Runs locally in your browser with zero uploads for privacy and speed.

Free online Screen Ruler. Runs locally in your browser with zero uploads for privacy and speed.

Free online screenshot annotator: draw pen, rectangles, arrows, and text, with undo/redo and PNG export. Runs locally.

Free online Seal Extractor. Runs locally in your browser with zero uploads for privacy and speed.

Free online seal forgery suspicion detector: Heuristic analysis of red seals based on pixel features, outputs suspicion score and mask preview (for reference only).

Free online signature generator. Draw a handwritten signature and export a transparent PNG locally in your browser.

Convert speech to text in your browser using the Web Speech API.

Free online sprite sheet generator: Merge multiple images to generate sprite PNG, export coordinates JSON and basic CSS (pure frontend local processing).

Free online SQL Formatter. Runs locally in your browser with zero uploads for privacy and speed.

Free online SSL/HTTPS checker: Test site HTTPS reachability, response status codes, final URLs and response time (static site uses public proxy).

Free online subtitle tool: Supports SRT/VTT/ASS conversion, timeline offset/speed adjustment, UTF-8/GBK encoding conversion, pure frontend local processing.

Free online SVG Converter. Runs locally in your browser with zero uploads for privacy and speed.

Free online SVG optimization compression: Remove comments/metadata/title/desc and compress whitespace to generate smaller SVG (pure frontend local processing).

Free online Text Diff. Runs locally in your browser with zero uploads for privacy and speed.

Convert text to natural speech with multiple voices and speed controls.

Free online Timer. Runs locally in your browser with zero uploads for privacy and speed.

Free online Timestamp Converter. Runs locally in your browser with zero uploads for privacy and speed.

Free online Timezone Converter. Runs locally in your browser with zero uploads for privacy and speed.

Free online TOML ↔ JSON converter tool: Supports TOML to JSON, JSON to TOML, copy output, pure frontend local operation.

Free online Unit Converter. Runs locally in your browser with zero uploads for privacy and speed.

Free online URL Encoder / Decoder. Runs locally in your browser with zero uploads for privacy and speed.

Free online URL Parser. Runs locally in your browser with zero uploads for privacy and speed.

Free online UUID Generator. Runs locally in your browser with zero uploads for privacy and speed.

Free online video compressor to MP4 (H.264) with scaling and CRF quality control. Runs locally.

Free online video format converter (MP4/WebM/MKV/MOV/AVI) with basic scaling/FPS/CRF settings. Runs locally.

Free online Video Player. Runs locally in your browser with zero uploads for privacy and speed.

Free online Video to GIF Converter. Runs locally in your browser with zero uploads for privacy and speed.

Free online Video Trimmer. Runs locally in your browser with zero uploads for privacy and speed.

Free online Websocket Tester. Runs locally in your browser with zero uploads for privacy and speed.

Free online Word Compressor. Runs locally in your browser with zero uploads for privacy and speed.

Free online Word Counter. Runs locally in your browser with zero uploads for privacy and speed.

Edit metadata in Word (DOCX), Excel (XLSX) and PDF: creation/modification time, author, title, keywords, company/manager, and custom properties. Runs locally in your browser.

Free online X.509 certificate parser viewer: Supports PEM/DER, displays Subject/Issuer/Validity Period/Fingerprint/SAN and other information, pure frontend local processing.

Open and preview .xmind files online. Runs locally in your browser (no uploads) with Canvas preview and Markdown outline export.

Free online XML to JSON Converter. Runs locally in your browser with zero uploads for privacy and speed.

Free online ZIP encrypt decrypt tool: Locally package ZIP and encrypt to JSON with AES-256-GCM, supports decrypting to restore ZIP.