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321Kit · 510 free online tools

Online tools for everyday work.

Test network quality and work with PDFs, images, audio, video, text and everyday calculations. No signup, with a clear processing location for every task.

510 tools 10 categories No signup
What do you need to do? Describe the problem in your own words. Matching happens in this browser.
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QR Workspace · Editable after printing

Print once. Update the page, form and follow-up anytime.

Create an editable QR workflow for inspections, events, menus and handoffs. The public QR address stays stable while the content changes.

Create a free workspace See the complete product

10 active codes free No card required Pro from $9/month

  1. CreateBuild a mobile page and attach one reusable form.
  2. PublishKeep the same public QR address when content changes.
  3. Follow upReview submissions and opt in to email digests.

Featured workflows

Start with a specific job

Jump straight into calendar rules, Word files, media, publishing, advertising and SEO. No account needed.

Calendar

Nth Weekday of Month

Find the first through fifth, or last, requested weekday in a calendar month.

Open tool → Word

DOCX Metadata Inspector

Read Word core properties such as title, creator, subject and dates.

Open tool → Video

Extract Frames from Video

Extract PNG frames at a chosen time interval, with a hard maximum of 60 images.

Open tool → Publishing

RSS Feed Generator

Generate RSS 2.0 XML from channel settings and bounded item blocks.

Open tool → Audio

Audio Sample Rate Converter

Resample audio to 22.05, 44.1 or 48 kHz and export MP3.

Open tool → Advertising

Break-even & Target ROAS Calculator

Turn order costs and a profit goal into the minimum and target return your advertising needs.

Open tool → SEO

Meta Description Length Checker

Check description characters, UTF-8 bytes, approximate rendered width, and desktop or mobile search-result layout in a live local preview.

Open tool → SEO

Robots.txt Tester

Test one URL path against Allow and Disallow rules for a selected user agent.

Open tool →

Included utilities

Browse 510 tools

Popular entries appear below. Search above to find every tool, or open a category for its complete list.

Network

Speed, latency, stability, DNS and VPN comparison

View all 5
Internet Speed & Network Quality Test Latency & Jitter Test Connection Stability Monitor DNS Lookup & Latency Diagnostics VPN vs Direct Network Comparison

Developer

JSON, regex and QR codes

View all 116
JSON & YAML Workbench Regex Tester URL Encoder & Decoder Base64 Encoder & Decoder HTML Entity Encoder & Decoder JWT Decoder UUID v4 & NanoID Generator Unix Timestamp Converter JSON String Escape & Unescape Text Case Converter Whitespace Remover Line Sorter Duplicate Line Remover Text Reverser URL Slug Generator SHA-256 Hash Generator Query String Parser Regex Escape Tool Number Base Converter CSV & JSON Converter

Image

Compress, resize, convert and OCR

View all 71
Image Compressor Image Resizer Image Format Converter Image Cropper Image Rotator & Flipper Image Filter Editor Text Watermark Tool Image Pixel Color Picker Image to Data URL Converter SVG to PNG Converter Favicon PNG Generator Image Collage Maker Circle Image Cropper Rounded Corner Image Maker Image Border Adder Image Pixelator Image Blur Tool Image Sharpener Black and White Threshold Tool Image Color Inverter

PDF

Merge, split, convert images and impose pages

View all 47
PDF Merger PDF Splitter PDF Page Extractor PDF Page Deleter PDF Page Reorderer Reverse PDF Pages Rotate PDF Pages Duplicate PDF Pages Extract Odd PDF Pages Extract Even PDF Pages Extract First PDF Page Extract Last PDF Page PDF Page Interleaver Prepend or Append PDF Insert PDF Pages Insert Blank PDF Page Append Blank PDF Page PDF Page Counter PDF Page Size Inspector PDF Metadata Viewer

Text & Content

Count words, characters, sentences and emoji

View all 49
Word & Character Counter English Stop Word Remover English Readability Score Analyzer HTML to Markdown Converter Markdown Link Extractor Markdown Heading Outline Markdown Table of Contents Generator Markdown Table Generator Markdown Table Formatter Markdown Table to CSV Converter CSV to Markdown Table Converter Markdown Task List Converter vCard Generator vCard Parser ICS Calendar Event Generator ICS Event Parser SRT Subtitle Validator SRT to WebVTT Converter WebVTT to SRT Converter Subtitle Time Shifter

Calculators

Dates, finance and ecommerce decisions

View all 96
Weighted Average Calculator Permutation & Combination Calculator Factorial Calculator Exponent & Root Calculator Logarithm Calculator Arithmetic Sequence Calculator Geometric Sequence Calculator Linear Equation Solver Two-Equation System Solver Matrix Determinant Calculator 2×2 Matrix Inverse Vector Magnitude Calculator Vector Dot Product Calculator Coordinate Distance Calculator Slope Calculator Rectangle Calculator Trapezoid Calculator Ellipse Calculator Circular Sector Calculator Regular Polygon Calculator

Audio & video

MP4, MP3, compression and precise trimming

View all 50
Audio to MP3 Converter Audio to WAV Converter Audio to OGG Vorbis Converter Audio to FLAC Converter Audio to AAC Converter Audio to M4A Converter Audio to Opus Converter Video to MP4 Converter Video to WebM Converter Video to MOV Converter Video to MKV Converter Video to GIF Converter Extract Audio from Video Video to MP3 Converter Video to WAV Converter Audio Trimmer Merge Two Audio Files Audio Volume Adjuster Audio Loudness Normalizer Audio Fade-In Maker

Office files

DOCX table extraction

View all 40
CSV to XLSX File TSV to XLSX File JSON to XLSX File XLSX to CSV File XLSX to TSV File XLSX to JSON File XLSX to HTML Table XLSX Sheet Lister XLSX Workbook Statistics XLSX Metadata Inspector XLSX Sheets to CSV XLSX Column Selector XLSX Empty Row Remover XLSX Duplicate Row Remover XLSX Sheets Merger Multiple CSV Files to XLSX Spreadsheet Formula Inspector Spreadsheet Date Normalizer Spreadsheet Cell Type Profiler Spreadsheet Header Renamer

SEO & web

Site checks and rule validation

View all 30
HTML Heading Outline Extractor HTML Link Extractor HTML Image Alt Auditor HTML Canonical Auditor HTML Hreflang Auditor HTML Meta Robots Analyzer HTML Social Meta Analyzer HTML Content Text Extractor HTML Table to CSV Converter HTML Form Field Extractor HTML Language Attribute Auditor HTML Anchor Text Auditor Title Tag Length Checker Meta Description Length Checker Canonical Link Tag Generator Hreflang Link Tag Generator Robots Meta Tag Generator Robots.txt Generator Robots.txt Tester Sitemap URL Extractor

Ecommerce

Ads, profit and pricing

View all 6
Break-even & Target ROAS Calculator Max CPC Calculator Discount Impact Calculator Ecommerce LTV & Max CAC Calculator Price Increase Impact Calculator Ecommerce Return Rate Profit Calculator
Optional AI assist · BetaRepair and explain JSON / YAML errors

Local formatting stays the default. Content is sent only after confirmation for that request.

Open