151 working tools · 8 categories · no account needed
The tools you need,without the upload.
Developer utilities, subnet and DNS checks, PDF and image converters, and everyday calculators — all free, all fast, and almost all running entirely inside your browser.
- Tools
- 151
- Categories
- 8
- Server uploads
- 0
- Signups
- 0
Popular starting points
Start with a popular tool
Eight tools that make a practical starting point — each one works without an account and finishes in the same tab.
IPv4 Subnet Calculator
Network, broadcast, host range and binary working for IPv4.
Public IP Lookup
See your public IP, ISP, ASN and approximate location.
DNS Lookup
Query DNS records over DoH with multiple record types.
SSL Certificate Checker
Check TLS issuer, expiry and covered domains.
HTTP Header Checker
Response headers plus a practical security-header audit.
JSON Formatter
Beautify or minify JSON, with precise error positions.
JWT Decoder
Read JWT claims and optionally verify HMAC signatures.
Password Generator
Cryptographically secure passwords with entropy scoring.
Browse by task
Eight categories, no filler
Every tool has its own page with a worked example, safety notes and a clear data-handling summary. Categories are deliberately focused so you can scan them in seconds.
PDF & Documents
Merge, split, edit, sign, rotate, watermark and convert PDFs without sending files to a server.
Images & Design
Compress, resize, convert, crop and style images with full control over quality.
Developer Tools
JSON, Base64, JWT, hashes, IDs, text transforms and data conversion — no uploads, no signup.
JSON Formatter
Beautify or minify JSON, with precise error positions.
JWT Decoder
Read JWT claims and optionally verify HMAC signatures.
Password Generator
Cryptographically secure passwords with entropy scoring.
Word Counter
Words, characters, sentences, paragraphs and reading time.
Network & Cybersecurity
DNS, subnetting, IP, mail authentication, TLS and HTTP checks built for real troubleshooting.
IPv4 Subnet Calculator
Network, broadcast, host range and binary working for IPv4.
Public IP Lookup
See your public IP, ISP, ASN and approximate location.
DNS Lookup
Query DNS records over DoH with multiple record types.
SSL Certificate Checker
Check TLS issuer, expiry and covered domains.
SEO & Website
Audit metadata, preview snippets, and generate robots.txt, sitemaps and hreflang.
Meta Tag Analyzer
Audit the head of a page for SEO and sharing tags.
SERP Snippet Preview
Preview how a search result will look.
Canonical URL Checker
Spot canonical mismatches before they split ranking signals.
Hreflang Generator
Create valid hreflang tags for language variants.
Business & Marketing
Campaign links, QR codes, email signatures and margin calculations for small teams.
UTM Builder
Create consistent, analysable campaign links.
QR Code Generator
Create downloadable PNG and SVG QR codes.
Email Signature Generator
Generate an email signature that survives mail clients.
Campaign ROI Calculator
Profit, ROI, ROAS and payback from two numbers.
Student & Education
Citations, GPA maths and study helpers with the formulas shown.
APA Citation Generator
APA 7 references for books, articles and websites.
MLA Citation Generator
MLA 9 works-cited entries in a consistent format.
Harvard Citation Generator
Harvard author–date references for common sources.
GPA Calculator
Weighted GPA from credits and grades.
Calculators & Productivity
GST, EMI, SIP, dates, time zones, units, data sizes and interest with the maths shown.
Privacy, explained plainly
Local processing is the default, not a marketing line
Formatting JSON, decoding a JWT, merging PDFs and compressing images all happen through JavaScript on your device. The page loads once; after that, your data has nowhere to go. A small number of network tools need public lookups, and each one says exactly which service it contacts.
Your files stay put
Developer, PDF and image tools process data in your browser. Sensitive input is never uploaded to a server.
One tab, no waiting
No account wall, no email capture, no queue. Open a tool, get an answer, close the tab.
Built for slow networks
Static pages and small JavaScript bundles load quickly on mobile data and mid-range phones.
Honest about limits
Network checks explain exactly which public services they contact. Nothing is described as more private than it is.
Recently updated
Fresh fixes and additions
Each page shows the date it was last updated, so you can judge how current it is.
Guides
Learn the why, not just the click
Short, practical explainers written to complement the tools — no padded listicles.
Networking
CIDR and subnetting: how to read /24, /25 and everything in between
A practical walkthrough of CIDR notation, network and broadcast addresses, usable host counts and how to split a /24 without memorising tables.
Security
JWT decoding is not verification: what each step actually proves
Decoding a JWT only reveals its claims. Verification checks the signature with a key. Here is why the difference matters for security reviews and debugging.
Security
The HTTP security headers worth checking — and what bad values look like
A short audit checklist for CSP, HSTS, X-Content-Type-Options, Referrer-Policy, Permissions-Policy and frame protection, with realistic failure examples.
Bookmark the toolkit you will use all week
Press Ctrl + D — or on a Mac, ⌘ + D — and open the command palette with ⌘K whenever you need a tool.