Private tools for audio, PDFs, and developer filesExecutedon Your Machine
Extract 320 kbps MP3 audio from video, merge and redact confidential PDFs, compress WebP images, and inspect JWT payloads inside your browser’s local memory—zero server uploads.
Dev & Code
JSON, JWT & SQL
PDF Suite
Merge, Split & Sign
Audio Studio
Dolby & 320kbps MP3
Image Studio
Compress & Vector SVG
Data & Files
CSV, JSON & Excel
Text & Writing
Diff, Regex & Markdown
Quick Utilities
QR Studio, Base64 & Hash
Time & Calc
Age, Dates & Units
Core Flagship Studios & Specialized Suites
Lead with our two primary media and document engines, or jump directly into a specialized developer suite
Audio & Video
In-browser 32-bit float DSP audio workstation. Extract 320 kbps MP3 from MP4/MKV/MOV containers, reverse waveforms, shift pitch/tempo, isolate vocals, and master Dolby spatial acoustics.
Data & Spreadsheets
Local spreadsheet and structured data workbench. Convert CSV to JSON, flatten JSON into Excel (.xlsx), profile dataset columns, repair malformed JSON, and print commercial invoices.
Date & Calculators
Chronological age calculators accurate to the second, upcoming birthday milestone trackers, and bidirectional metric/imperial scientific unit converters.
Developer & Code Tools
Client-side developer and security engineering suite. Inspect JWT tokens, convert cURL commands to code, build cron schedules, format SQL, audit HTTP headers, and run sandboxed HTML.
Image & Graphics
On-device photo and vector graphics optimization. Compress PNG, JPEG, and WebP images with perceptual quantization, resize dimensions, sample WCAG color palettes, and rasterize 4K SVG vectors.
PDF & Documents
Local PDF manipulation in browser memory. Merge, split, reorder, extract pages, convert PDF to editable Word DOCX, redact confidential text, watermark, and sign without uploading files.
Text & Writing
Precision text processing utilities for live split-screen Markdown authoring, regular expression debugging, side-by-side line diffing, and character/case transformations.
Utilities & Codes
Essential browser utilities including custom vector QR Code generation, binary Base64 encoding/decoding, and Web Crypto SHA-256/SHA-512 file checksum verification.
Audio & Video
In-browser 32-bit float DSP audio workstation. Extract 320 kbps MP3 from MP4/MKV/MOV containers, reverse waveforms, shift pitch/tempo, isolate vocals, and master Dolby spatial acoustics.
PDF & Documents
Local PDF manipulation in browser memory. Merge, split, reorder, extract pages, convert PDF to editable Word DOCX, redact confidential text, watermark, and sign without uploading files.
Data & Spreadsheets
Local spreadsheet and structured data workbench. Convert CSV to JSON, flatten JSON into Excel (.xlsx), profile dataset columns, repair malformed JSON, and print commercial invoices.
Date & Calculators
Chronological age calculators accurate to the second, upcoming birthday milestone trackers, and bidirectional metric/imperial scientific unit converters.
Developer & Code Tools
Client-side developer and security engineering suite. Inspect JWT tokens, convert cURL commands to code, build cron schedules, format SQL, audit HTTP headers, and run sandboxed HTML.
Image & Graphics
On-device photo and vector graphics optimization. Compress PNG, JPEG, and WebP images with perceptual quantization, resize dimensions, sample WCAG color palettes, and rasterize 4K SVG vectors.
Text & Writing
Precision text processing utilities for live split-screen Markdown authoring, regular expression debugging, side-by-side line diffing, and character/case transformations.
Utilities & Codes
Essential browser utilities including custom vector QR Code generation, binary Base64 encoding/decoding, and Web Crypto SHA-256/SHA-512 file checksum verification.
Featured Workbench Spotlight
Most-used client-side converters and studio processors
Studio Master & Dolby Spatial Audio Enhancer
Elevate any song with Dolby Atmos-style 3D spatial field expansion, sub-bass punch, vocal air sparkle, and dynamic studio mastering compression. Free and works offline.
All Tools Directory· 103 tools
Select any utility below to launch its local browser workbench immediately.
8D Audio & 3D Spatial Panner Studio
Transform regular stereo audio into immersive 3D/8D rotating surround sound with binaural panning, room acoustic simulation, and export options.
Add Page Numbers to PDF
Stamp custom page numbers, Page X of Y formats, or roman numerals at top/bottom document margins with font size and offset controls.
Age Calculator
Calculate exact chronological age down to the second, Western & Chinese zodiac signs, and life milestones.
Audio Reverb & Acoustic Room Studio
Add studio-grade acoustic reverb, vocal booth depth, hall reverberation, and space echo to any audio track with live dry/wet mix controls.
Audio Reverser & Backward Sound Studio
Reverse songs, voice recordings, and sound effects with speed/pitch controls, reverse reverb swell, ping-pong loops, and lossless WAV or MP3 export.
Audio Spectrogram & Waveform Generator
Generate high-resolution visual frequency spectrograms and artistic waveform graphics from any sound with customizable color themes and PNG/SVG export.
Audio to Audio Converter
Convert any audio file (MP3, WAV, AAC, FLAC, M4A, OGG, Opus, AIFF) into all major audio formats with custom bitrate, sample rate, and channel controls.
Audio Trimmer & Waveform Cutter
Precision visual waveform audio cutter with millisecond trim controls, audio fade-in/fade-out, volume gain, and high-bitrate MP3/WAV export.
Base64 File & Image Studio
Encode any image, audio, or document to Base64 data URIs, or decode Base64 strings back to downloadable files with live preview. Completely free and works offline.
Bass Booster & 10-Band Graphic Equalizer
Boost low-end sub bass, customize 10-band frequency equalizer levels, and shape sound profiles with genre presets and lossless audio export.
Birthday Calculator
Calculate live countdowns to your next birthday, multi-year weekend forecast, and milestone tracking.
BPM & Tap Tempo Detector
Automatically detect beats per minute (BPM) from music tracks or tap to find exact tempo with built-in metronome and rhythmic frequency analyzer.
Chmod Permissions Calculator & Linux Studio
Visual Linux and Unix file permissions calculator. Convert between octal and symbolic modes, toggle SUID/SGID/Sticky bits, and generate recursive bash commands.
Color Palette & Contrast Studio
Extract harmonic color palettes from any photo with live eyedropper, convert between HEX/RGB/HSL/CMYK, and test WCAG 2.1 contrast accessibility. Free and works offline.
Cron Expression Builder & Explainer
Visual interactive cron schedule builder with plain-English human translation and next 10 scheduled execution dates simulator.
Crop PDF Margins & Bounding Box
Trim unwanted white borders, header/footer margins, and crop PDF page areas with custom point coordinates directly on your device.
CSV & Data Table Profiler & Analyzer
Inspect, profile, and compute summary metrics (mean, median, min, max, null counts) for CSV datasets and spreadsheets with export to JSON, TSV, or Markdown tables.
CSV to JSON & JSON to CSV Converter
Convert CSV/TSV spreadsheets to JSON arrays or transform JSON objects to CSV tables with custom delimiters, type detection, and interactive data grid. Free and works offline.
cURL to Code Converter
Convert cURL commands to production-ready code for JavaScript (Fetch & Axios), Python (Requests & Httpx), Go, Node.js, PHP, and Rust.
Extract Images from PDF Document
Extract and render high-resolution raster images from PDF pages into lossless PNG files with instant individual downloads.
Flatten PDF Forms & Annotations
Permanently bake interactive form fields, checkboxes, and annotations into static document layers to prevent tampering.
Git Workflow & Command Studio
Interactive visual Git workflow architect and command generator. Undo commits safely, generate cherry-picks, rebase, squash commits, and master branching recipes.
Hash & Checksum Verifier
Calculate cryptographic SHA-256, SHA-512, SHA-384, SHA-1, and MD5 hashes for text and files of any size, with 1-click checksum verification. Completely free and works offline.
HTML Entity & Unicode Code Point Studio
Bidirectional HTML entity encoder and decoder with Named, Decimal, Hexadecimal formats, JavaScript Unicode escapes, CSS escapes, and searchable character catalog.
HTML Formatter & Live Studio Playground
CodePen-style live HTML, CSS, and JavaScript editor and code formatter. Real-time sandboxed preview rendering videos, images, and audio with integrated developer console and live JS REPL.
HTTP Security Headers & Status Code Studio
Interactive security headers generator (CSP, HSTS, CORS, X-Frame) & authoritative HTTP status code reference with RFC specs and SEO crawler impact.
Images to PDF Converter
Convert and combine any image formats (JPG, PNG, WebP, GIF, BMP, SVG, AVIF, TIFF) into a high-end PDF with custom page rotation, reordering, and file renaming.
Instant QR Code Studio
Generate customizable, high-resolution QR codes for websites, Wi-Fi networks, emails, and phone numbers with custom colors and instant PNG/SVG download.
Interactive Regex Studio & Tester
Real-time regular expression tester with capture group breakdown, syntax error validation, common pattern presets, and regex substitution. Completely free and works offline.
JSON Cleaner & Formatter
Format, validate, repair common syntax slips, sort keys alphabetically, and minify JSON with real-time structural inspection.
JSON to Excel / CSV Converter
Convert JSON arrays or nested objects into organized Microsoft Excel spreadsheets and CSV files with automatic flattening and live preview.
JSON to TypeScript & Zod Schema Converter
Transform raw JSON objects into clean TypeScript interfaces, type aliases, Zod validation schemas, and JSON Schema definitions with custom casing and nullability.
JWT Debugger & Token Inspector
Decode JSON Web Tokens, inspect headers and claims, verify HMAC-SHA256 signatures with Web Crypto, and audit expiration dates with zero server leaks.
Markdown Live Editor & Exporter
Real-time split-screen Markdown editor with GitHub-flavored rendering, word statistics, and 1-click export to HTML, PDF, or Markdown files. Completely free and works offline.
PDF Merger & Combiner
Combine multiple PDF documents into a single organized file with drag-and-drop reordering, page counter, and instant download.
PDF Page Organizer & Splitter
Visually organize, reorder, rotate, extract specific page ranges, or split every page into separate PDF documents with instant ZIP download.
PDF Password & Security Studio
Encrypt PDFs with password protection or unlock password-protected PDF files directly on your device. Completely free and works offline.
PDF to Text Plaintext Extractor
Extract raw text, paragraphs, and formatted lines from PDF documents into copyable plaintext with 1-click clipboard copy and TXT download.
PDF to Word (DOCX) Converter
Transform any PDF document into an editable Microsoft Word (.docx) file with headings, bullet points, customizable typography, and custom file renaming.
Pitch Shifter & Tempo Changer Studio
Change the pitch, key, and playback speed of any song or voice recording independently by semitones and cents with high-fidelity MP3/WAV export.
Private Invoice & Receipt Generator
Create professional, print-ready invoices and receipts with multi-currency support, tax/discount calculations, and instant PDF download. Completely free and works offline.
Redact PDF Sensitive Information
Permanently black out confidential numbers, personal information, and sensitive text regions directly on the document canvas.
Remove PDF Metadata & Sanitizer
Strip hidden author identities, software fingerprints, creation timestamps, and printer metadata for complete document privacy.
Rotate PDF Pages Permanently
Rotate all or odd/even PDF pages 90°, 180°, or 270° clockwise with permanent orientation saving and zero quality loss.
Sign PDF & Digital Verification Seal
Apply digital signature certificates, authorized visual approval stamps, and local audit timestamps directly to PDF documents.
Smart Image Compressor
Shrink JPG, PNG, and WebP images up to 80% without visible quality loss using in-browser hardware canvas acceleration.
SQL Query Formatter & Minifier
Beautify, format, indent, and minify SQL queries for PostgreSQL, MySQL, SQLite, T-SQL, and BigQuery with configurable keyword casing.
Studio Master & Dolby Spatial Audio Enhancer
Elevate any song with Dolby Atmos-style 3D spatial field expansion, sub-bass punch, vocal air sparkle, and dynamic studio mastering compression. Free and works offline.
SVG to Image Converter
Convert SVG vector files or raw code to high-resolution PNG, JPEG, and WebP at 1x, 2x, 4x, 8x, or custom dimensions with transparency controls. 100% free and works offline.
Text & Document Diff Checker
Visual side-by-side and unified text comparison tool with character-by-character diffing, whitespace controls, and patch export. Completely free and works offline.
Universal Image Converter & Resizer
Batch convert images between WebP, PNG, JPEG, and AVIF with custom pixel scaling, aspect ratio locking, quality control, and ZIP download.
Universal Unit Converter
High-precision metric and imperial converter for length, mass, temperature, digital data, speed, and time.
Unix Timestamp & Epoch Converter
Live Unix epoch clock with bidirectional seconds/ms/μs conversion, relative time calculations, date offset math, and batch log converter.
Video to Audio Converter
Extract and convert any video file (MP4, WebM, MKV, MOV, AVI, WMV, FLV) into high-fidelity audio (MP3, WAV, AAC, FLAC, M4A, OGG) with customizable bitrate and quality.
Vocal Remover & Karaoke Studio
Isolate or remove vocals from songs to create karaoke instrumentals or acapella vocal tracks with stereo phase cancellation and bass preservation.
Volume Booster & Loudness Normalizer Studio
Boost audio volume up to +24dB, normalize peak loudness to prevent clipping distortion, and downmix multichannel audio to stereo or mono.
Watermark PDF Stamper Studio
Stamp angled confidential, draft, or custom text watermarks with opacity, color, and font size controls across all PDF pages.
Word Counter & Case Converter
Real-time word, character, sentence count, reading time calculator, and one-click case converter (Title Case, UPPERCASE, camelCase, snake_case).
Need a Specific File Converter or Developer Utility?
We build and ship new client-side WebAssembly tools weekly based on engineering requests. Tell us the exact format or workflow you need.
Why We Run Compiled WebAssembly in Your Browser Instead of Cloud Servers
Most online converters upload your tax PDFs, private voice recordings, and production JSON payloads to shared cloud storage buckets before processing them in a remote queue. Super ToolKit eliminates the remote server altogether.
100% On-Device WebAssembly & 32-Bit Float Web Audio DSP
When you drop a 1.4 GB video file or a 200-page PDF contract into Super ToolKit, the browser reads the file directly from disk into a local ArrayBuffer. Compiled C/C++ and Rust WebAssembly modules demux audio streams, rasterize vector pages, and compute SHA-256 digests directly on your device’s CPU cores.
“You can verify our zero-upload architecture yourself: open your browser’s Network Inspector (F12), disconnect Wi-Fi, and run any PDF merge or MP4-to-MP3 extraction. Zero packets leave your machine.”
Read Architecture Docs →
02. Volatile RAM Isolation & Zero Account Walls
Documents, audio tracks, and bearer tokens exist strictly inside your active browser tab’s volatile memory heap. Closing the tab immediately garbage-collects all buffers—no S3 buckets, no server access logs, no daily 2-file quotas, and no registration gates.
03. Offline Service Worker PWA (Airplane Mode Ready)
Install Super ToolKit onto macOS, Windows, Linux, iOS, or Android directly from your browser. All WebAssembly binaries and DSP worklets cache locally via our Service Worker for 100% offline operation.
Benchmark Audit: Client-Side WebAssembly vs. Cloud Upload Portals
Measured on a 500 MB MP4 audio extraction and a 45-page confidential PDF merge
| Evaluation Metric | Super ToolKit (Local WASM) | Legacy Cloud Converters (iLovePDF / CloudConvert) |
|---|---|---|
| File Processing Location | 100% In-Browser RAM Sandbox | Uploaded to remote AWS / GCP buckets |
| Upload & Queue Latency (500 MB File) | 0 ms upload · 3.8 sec local render | 45s–4 min upload + remote queue wait |
| Data Confidentiality & Retention | Zero bytes leave your device | Retained on 3rd-party servers 2–24 hours |
| Account Registration & Paywalls | None required · Unlimited batch size | Paywalled after 2–3 daily tasks |
| Offline / Airplane Mode Execution | Works 100% offline via Service Worker | Fails without active internet |
Dedicated Format Converters (Zero Server Upload)
Launch pre-configured format conversion pipelines directly in your browser tab:
Browse by Category Hub
Client-Side WebAssembly Privacy & Zero-Upload FAQ
Does Super ToolKit upload my files to a remote cloud server?▼
No. Super ToolKit executes 100% locally inside your web browser using compiled WebAssembly (Wasm), Web Audio API DSP, and HTML5 Canvas engines. Your videos, audio tracks, PDFs, images, and developer payloads never leave your device.
Are there any file size limits, daily conversion caps, or paywalls?▼
Never. Because all processing uses your own device CPU and RAM rather than paid cloud servers, Super ToolKit has zero daily limits, no 100MB upload caps, no watermarks, and requires no account registration or subscription.
Can I use Super ToolKit converters and developer utilities offline without internet?▼
Yes. Super ToolKit is an installable Progressive Web App (PWA). Once opened, our Service Worker caches the application shell and client-side WebAssembly modules so you can convert files, merge PDFs, and debug JWT or SQL queries in Airplane Mode.
What types of tools and format converters are included in Super ToolKit?▼
Super ToolKit includes 58+ dedicated workbenches and 18+ direct format-pair converters across 8 suites: Audio & Video DSP (MP4 to MP3, 8D Audio, Stem Splitter, Dolby Enhancer), PDF & Document tools, Developer Utilities (JSON to TypeScript, JWT Debugger, SQL Formatter), Image & SVG tools, Data & CSV analyzers, Text & Crypto hashes, QR/Barcode generators, and Date/Unit calculators.
How does Super ToolKit compare to CloudConvert, Convertio, and iLovePDF?▼
Unlike CloudConvert, Convertio, and iLovePDF—which upload your sensitive files to remote servers and enforce daily conversion quotas or file size caps—Super ToolKit processes everything in volatile browser memory with 0ms upload latency and complete GDPR/HIPAA-grade confidentiality.