Fast, private tools for developers and makers.
A growing toolbox of single-purpose utilities. Everything runs in your browser — your files never leave your device.
100% client-side
No sign-up · No uploads
SEO & meta
Generate the markup search engines read.
Meta tag generator
Build SEO + Open Graph meta tags.
robots.txt generator
Generate a valid robots.txt file.
Sitemap.xml generator
Build a sitemap from a URL list.
Schema markup generator
JSON-LD structured data for rich results.
Open Graph image generator
Design a social share image, export PNG.
UTM URL builder
Tag campaign links for analytics.
Encoding & JSON
Format, convert, encode and decode data.
Dev utilities
Everyday tools for developers.
Regex tester
Test regular expressions with live matches.
Cron expression visualizer
Explain cron and see next run times.
Epoch converter
Convert Unix timestamps to dates.
Diff checker
Compare two texts side by side.
Markdown to HTML
Convert Markdown to HTML and back.
Case converter
camelCase, snake_case, Title Case and more.
Generators
IDs, secrets, colors and random data.
QR & barcode
Scannable codes for anything.
Images
Compress, convert and clean images — in your browser.
Merge, split and edit PDFs privately.
Documents
Invoices, business cards and more.
Invoice generator
Full-featured invoice builder — line items, tax, logo, PDF.
Online invoice maker
Quick service invoice in the browser — no sign-up, no upload.
Create invoice online
Product/delivery invoice from a simple form → PDF.
Proforma invoice generator
Proforma invoices for quotes & customs.
Contractor invoice template
Bill labour and materials.
Freelance invoice template
Bill hourly or per project.
Lookups
Decode identifiers and query public registries.
WHOIS lookup
Look up domain registration records.
DNS lookup
Query A, AAAA, MX, TXT and more.
SSL certificate checker
Inspect a site’s TLS certificate.
HTTP header checker
Inspect a URL’s response headers.
IP address lookup
Geolocate an IP and find its network.
Reverse DNS lookup
Find the PTR hostname of an IP.
CSS & design
Visual CSS generators with live previews.
CSS Grid generator
Visual grid builder with live CSS.
CSS Flexbox generator
Build flex layouts with live preview.
Box-shadow generator
Compose box-shadow with a live preview.
Text-shadow generator
CSS text-shadow with live preview.
CSS clip-path generator
Polygon, circle and ellipse clip paths.
Border-radius generator
Per-corner border-radius with preview.
Network
IP, subnet and routing math — fully client-side.
Subnet calculator
IPv4 subnet, mask, range and host counts.
CIDR calculator
CIDR notation → range, mask, hosts.
Subnet mask calculator
Convert between mask, CIDR prefix and host count.
IPv4 to IPv6 converter
Map an IPv4 address to its IPv6 form.
IP to binary converter
IPv4 address ↔ binary and decimal int.
Finance & options
Options, trading and money math — educational, in your browser.
Options profit calculator
P/L, breakeven and ROI for calls and puts.
Black-Scholes calculator
Price an option and see all its Greeks.
Implied volatility calculator
Back out IV from an option’s market price.
Expected move calculator
Project a stock’s expected move from IV.
Covered call calculator
Returns if called away, breakeven and yield.
Iron condor calculator
Max profit, max loss and breakevens.
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