Free Developer & SEO Tools — No Login Required

All-in-One
SEO & Developer
Toolbox

A free, fast, privacy-friendly suite of tools for web developers, marketers, and site owners. Audit your SEO, check DNS records, look up WHOIS data, generate QR codes, format code, convert text — all in one place, no sign-up needed.

No login required Privacy-first Instant results Works on any site

Everything You Need to Optimize & Build

Each tool is free, browser-based, and designed to save you time. No accounts, no rate limits on basic use, no hidden paywalls.

robots.txt & ads.txt Validator

Confirm that search engine and advertisement crawlers can read your site root files. Detect missing `robots.txt`, `ads.txt`, and sitemap directives with a single check.

  • robots.txt root validation
  • ads.txt presence check
  • Sitemap directive extraction
  • Server-side fetch to avoid CORS issues
Validate Now

DNS Record Lookup

Query all DNS record types — A, AAAA, MX, NS, TXT, CNAME, SOA, CAA — in real time via Google DNS-over-HTTPS. Check SPF, DMARC, and DKIM email security configurations. Diagnose propagation issues and verify nameserver changes instantly.

  • All record types (A, MX, TXT, NS, SOA…)
  • SPF / DMARC / DKIM detection
  • Real-time via Google DoH
  • MX host A-record validation
Look Up DNS

MX & Email Deliverability Check

Verify that your domain is correctly configured to send and receive email. Detects MX records, identifies your mail provider (Google Workspace, Microsoft 365, Zoho, etc.), and checks for SPF, DMARC, and DKIM records. Includes recommended fixes for missing configurations.

  • MX record priority & host validation
  • Mail provider auto-detection
  • SPF / DMARC recommendation engine
  • Email deliverability score
Check Email Health

WHOIS & Domain Lookup

Look up domain registration details using the modern RDAP protocol. See registrar, registration and expiry dates, nameservers, DNSSEC status, and domain statuses. Get expiry warnings so you never accidentally lose a domain.

  • Registrar & registration dates
  • Expiry countdown & renewal alerts
  • Live nameserver comparison (RDAP vs DNS)
  • DNSSEC verification
Look Up Domain

IP Address & Network Info

Instantly see your public IP address, geolocation, ISP, ASN, and timezone. Also detects your local LAN IP via WebRTC, identifies your DNS resolver, checks for VPN/proxy usage, and displays an interactive map of your approximate location.

  • Public & local IP detection
  • VPN / proxy / Tor detection
  • DNS resolver identification
  • Interactive geolocation map
Check My IP

QR Code Generator

Generate high-quality QR codes for URLs, plain text, email addresses, phone numbers, Wi-Fi network credentials, and vCard contacts. Customize foreground/background colors, set the output size up to 1200px, and download as SVG, PNG, or JPG.

  • URL, text, email, phone, Wi-Fi, vCard
  • Custom colors & sizes up to 1200px
  • Download as SVG, PNG, or JPG
  • Error-correction level H (30%)
Create QR Code

Text Case Converter

Transform any text into 13 different cases instantly. Convert between UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, dot.case, aLtErNaTiNg, and iNVERSE case. Includes word, character, sentence, and line counters.

  • 13 conversion modes
  • camelCase, snake_case, kebab-case for devs
  • Real-time stats (words, chars, lines)
  • One-click copy for every variant
Convert Text

Code Formatter & Beautifier

Instantly beautify or minify code in multiple languages. Supports JSON (with syntax validation), HTML, CSS, JavaScript, PHP, Python, SQL, XML, and Markdown. Choose your indentation (2 spaces, 4 spaces, or tabs), upload files, and download the formatted output.

  • JSON, HTML, CSS, JS, SQL, XML, PHP, Python
  • Format and Minify modes
  • File upload & download support
  • Configurable indentation
Format Code

Number & UUID Generator

Generate random data for testing, development, and data science. Supports random integers, floats, arithmetic sequences, UUID v4/v7, Nano IDs, CUIDs, secure passwords, Unix timestamps, hex/binary/base64 strings, and Gaussian-distributed numbers. Export as lines, CSV, JSON, or PHP arrays.

  • UUID v4, v7, Nano ID, CUID
  • Secure password generator
  • Gaussian / normal distribution
  • Export as CSV, JSON, PHP array
Generate Numbers

Colour Code Generator & Converter

Pick any color with a visual canvas picker and instantly convert between HEX, RGB, HSL, HSB/HSV, and CMYK. Auto-generates tints, shades, complementary, analogous, and triadic palettes. Checks WCAG contrast ratios and exports ready-to-use CSS custom properties.

  • HEX ↔ RGB ↔ HSL ↔ HSB ↔ CMYK
  • Auto tints, shades & harmonies
  • WCAG contrast ratio checker
  • CSS variable export
Pick a Color

Browser & User Agent Analyzer

Instantly detect your current browser name, version, rendering engine, operating system, screen resolution, device pixel ratio, connection type, and WebGL renderer. Also includes a user agent string parser — paste any UA string to identify the browser, OS, and device type.

  • Browser, engine & OS detection
  • Screen, viewport & DPR info
  • WebGL renderer fingerprint
  • UA string parser for any browser
Check Browser

Website Asset Downloader

Download all assets from any web page — images, CSS, JavaScript, fonts, PDFs, and documents — in a single click. Uses deep scanning to find resources referenced inside CSS and JS files, with CDN fallback, proxy rotation for rate-limited servers, and ZIP export with auto-cleanup.

  • CSS url() and JS import deep scan
  • 12× parallel download threads
  • CDN fallback + proxy rotation
  • ZIP export, 200+ file types
Download Assets

Hash Generator

MD5, SHA-1, SHA-256, SHA-512, SHA-3 & HMAC — compare & verify hashes instantly, entirely client-side.

  • 5 hash algorithms + HMAC
  • Compare & verify hashes
  • Runs 100% in your browser
Generate Hash

JWT Decoder & Inspector

Paste any JWT — decode header, payload, verify expiry, check claims. Nothing sent to server.

  • Decode header & payload
  • Expiry countdown & status
  • All standard claims displayed
Decode JWT

SSL / TLS Certificate Checker

Check cert validity, expiry countdown, issuer, SANs, HSTS status & HTTP/2 support.

  • Expiry days remaining
  • Cert chain & issuer info
  • HSTS & HTTP/2 check
Check SSL

HTTP Security Headers

Scan CSP, HSTS, X-Frame-Options, Referrer-Policy, Permissions-Policy — graded A–F.

  • A–F security grade
  • 9 security headers checked
  • Actionable descriptions
Scan Headers

Base64 Encoder / Decoder

Text, URLs and file-to-Base64 conversion. URL-safe & standard variants.

  • Encode & decode text
  • File to Base64 support
  • URL-safe mode
Encode / Decode

URL Encoder / Decoder

Percent-encode, decode, parse query strings & build URLs from parts.

  • Encode & decode URLs
  • URL parser with all components
  • Query param breakdown
Encode URL

JSON ↔ YAML ↔ TOML

Convert between formats instantly. Pretty-print, minify & validate JSON, YAML and TOML.

  • JSON ↔ YAML ↔ TOML
  • Pretty-print & minify
  • Syntax error detection
Convert Format

CSV / JSON / XML Converter

Paste CSV → get JSON array or XML. Paste JSON → get CSV. Smart column detection.

  • CSV ↔ JSON ↔ XML
  • Smart column detection
  • Pretty & minified output
Convert Data

Unix Timestamp Converter

Convert timestamps ↔ human dates. Live clock, relative time & ISO 8601 output.

  • Live current timestamp
  • Timestamp → multiple formats
  • Date → Unix & ISO 8601
Convert Time

Regex Tester & Explainer

Live regex with match highlighting, group capture display, flags & match statistics.

  • Live match highlighting
  • Capture group display
  • Flag toggles (g, i, m, s, u)
Test Regex

Text / Code Diff Checker

Side-by-side or unified diff. Character, word, or line granularity with color-coded changes.

  • Split & unified views
  • Char / word / line diff
  • Added / removed stats
Compare Text

Cron Expression Builder

Visual cron builder + tester. Shows next 10 run times & explains expression in plain English.

  • Visual field builder
  • Next 10 run times
  • Quick presets
Build Cron

Lorem Ipsum Generator

Paragraphs, sentences, words or lists — Lorem Ipsum & Hipster Ipsum variants.

  • Paragraphs, sentences, words
  • Classic & Hipster variants
  • Customizable count
Generate Text

Markdown Preview & Editor

Split-pane live Markdown with GitHub Flavored Markdown support. Export to HTML.

  • Live split-pane preview
  • GFM tables, code blocks
  • Export to HTML file
Open Editor

CSS Gradient Generator

Visual linear, radial & conic gradient builder. Copy as CSS or Tailwind. Presets included.

  • Linear, radial & conic
  • Multi-stop color control
  • One-click CSS copy
Build Gradient

Box Shadow & Filter Builder

Visual CSS box-shadow builder with layer stacking, blur/spread controls & live preview.

  • Multi-layer shadows
  • Inset shadow support
  • Live preview box
Build Shadow

OG Image & Meta Card Preview

Preview how any URL looks on Twitter/X, Facebook & LinkedIn social cards.

  • Twitter/X & Facebook previews
  • All OG & Twitter meta tags
  • Image, title & description
Preview Card

Favicon Generator

Upload any image → get .ico, 16×16, 32×32, 48×48, 192×192, 512×512 PNGs + HTML snippet.

  • 7 sizes generated
  • Download each size
  • Ready HTML <link> snippet
Generate Favicons

HTTP Response & Headers Inspector

Send requests and inspect status codes, headers, redirect chains, timing & response body.

  • GET, HEAD & POST support
  • Full redirect chain
  • All response headers
Inspect HTTP

Page Speed & Core Web Vitals

Analyze LCP, CLS, INP, TTFB via Google PageSpeed Insights. Mobile + desktop scores.

  • Performance, SEO, A11y scores
  • Core Web Vitals (LCP, CLS, INP)
  • Mobile & desktop strategies
Analyze Speed

Readability & Content Analyzer

Flesch-Kincaid, Gunning Fog, SMOG score. Word frequency heatmap & sentence length chart.

  • 4 readability scores
  • Top keyword frequency
  • Sentence length analysis
Analyze Text

Advanced Word & Character Counter

Reading time, speaking time, top keywords, unique words & sentence complexity.

  • 8 real-time stats
  • Reading & speaking time
  • Keyword frequency chart
Count Words

Simple, Fast, Free

1

Enter Your URL

Type or paste any domain or page URL into the tool of your choice. The domain is automatically shared across all network tools so you don't have to retype it.

2

Get Instant Results

Results appear in seconds — no server queues, no waiting. Our tools query real-time data sources like Google DNS-over-HTTPS and live RDAP registries.

3

Act on the Insights

Follow the prioritized recommendations, download sitemaps, copy keyword strategies, or export generated assets. Every tool is designed to produce actionable output.

Frequently Asked Questions

Are these tools completely free?
Yes. All tools on DEV Toolz Pro are completely free to use with no account, no subscription, and no hidden rate limits on basic use. The site is supported by non-intrusive advertising.
Do you store the URLs or data I enter?
No personal data is stored. URLs are used only to perform the requested lookup or crawl and are not logged or retained. The text case converter, code formatter, colour picker, number generator, and QR code tools all run entirely in your browser — nothing leaves your device.
How does the SEO auditor score pages?
The SEO score starts at 100 and deductions are applied for critical issues: missing title tag (−20), missing meta description (−20), noindex directive (−30), missing H1 (−15), multiple H1 tags (−10), images missing alt text (−3 each, up to −15), mixed content (−15), and various warnings. Bonus points are added for schema markup. The score gives you a quick health snapshot — not a guarantee of search ranking.
What DNS record types does the lookup tool support?
The DNS lookup tool supports A (IPv4), AAAA (IPv6), MX (mail exchange), NS (nameservers), TXT (text records, SPF, DMARC, DKIM), CNAME (aliases), SOA (start of authority), CAA (certificate authority authorization), and SRV (service records). All queries are made via Google DNS-over-HTTPS for accuracy and privacy.
Can I use the QR code generator for commercial purposes?
Yes. QR codes generated by this tool are yours to use for any purpose, including commercial use. The SVG and PNG outputs are clean, unbranded files at your chosen resolution.
How is the sitemap.xml generated?
After the SEO crawl completes, a sitemap is generated from all discovered pages, priority-ranked by URL depth and content type. You can download it as a standards-compliant sitemap.xml and submit it directly to Google Search Console to improve your site's indexing.
DEV Toolz Pro

Technical SEO Analyzer

Deep-crawl any site for meta tags, social previews, security, keyword density, broken links & XML sitemap generation.

Pages Crawled
0
Avg. SEO Score
0%
Queue
0
Status
Ready
Crawled Pages Click "Full Report" for detailed analysis

No data yet. Enter a URL above and click Analyze Site.

robots.txt & ads.txt Validator

Verify that your site exposes `robots.txt`, `ads.txt`, and sitemap directives correctly for search engines and AdSense.

This tool uses a server-side request to retrieve site files and bypass client-side CORS restrictions.

If your files were updated recently, CDN or Cloudflare cache can delay `robots.txt` / `ads.txt` availability. Wait a few minutes and recheck if the file is still missing.

DNS Record Lookup

Query A, AAAA, MX, NS, TXT, CNAME, SOA, CAA — via Google DNS-over-HTTPS

Check MX — Email Deliverability

Validates MX records, detects mail providers, checks SPF / DMARC / DKIM security

WHOIS & Nameserver Lookup

Registrar, dates, status, DNSSEC, live nameservers — via RDAP

Browser & User Agent

Your current browser environment and UA string parser

Browser Info DEBUG

Your current browser environment — useful for debugging user experience issues.

Collecting browser data…
User Agent Analyzer UA PARSER

Paste any UA string to detect browser, OS, engine, and device type.

IP Address Info

Your public IP, location, ISP, VPN/proxy detection, DNS resolver & browser fingerprint

Gathering your IP & network details…

Website Asset Downloader

Deep-crawl any page — CSS, JS, images, fonts, documents — with proxy rotation, CDN fallback & ZIP export

Features
12× parallel threads 3× auto-retry Proxy rotation on 429 CDN fallback CSS url() / @import JS import/require Webpack chunks Service workers ZIP export 1h auto-delete Browser-like fetch 200MB cap per file 200+ file types

Text Case Converter

Instantly transform text — uppercase, lowercase, title case, camelCase & more

0 chars 0 words 0 sentences 0 lines

QR Code Generator

Encode URLs, text, contacts & more — download as SVG, PNG, or JPG

Design Options
Preview

Enter content to generate QR code

Code Formatter

Beautify & format HTML, CSS, JavaScript, JSON, SQL and more

Input
0 lines · 0 chars
Output
Quick Examples

Number Generator

Random integers, floats, UUIDs, sequences, passwords & more

Generator Type
Generated Output

Colour Code Generator

Enter any colour code → auto-converts HEX · RGB · HSL · HSB · CMYK · CSS vars. Edit the visual picker or any field.

Colour Picker
Colour Codes — Edit Any Field
R
G
B
A%
S%
L%
Live Preview
#3B82F6
Dark text
Aa Bb Cc
Light text
Aa Bb Cc
Contrast Ratio (vs White)
AA Normal: 4.5:1
Auto Palettes
Tints (lighter)
Shades (darker)
Complementary
Analogous
Triadic
Saved Colours
No saved colours yet. Click "Save" to bookmark a colour.
CSS Export

Hash Generator

MD5, SHA-1, SHA-256, SHA-512, SHA-3 — compute & compare hashes client-side

JWT Decoder & Inspector

Decode header, payload, check expiry & claims — nothing sent to server

SSL / TLS Certificate Checker

Check cert validity, expiry, chain, cipher suite & security headers

HTTP Security Headers

Scan CSP, HSTS, X-Frame-Options, Referrer-Policy — grade A–F

Base64 Encoder / Decoder

Text, URLs, and file-to-base64 — URL-safe & standard variants

URL Encoder / Decoder

Percent-encode, decode, parse query strings & build URLs from parts

JSON ↔ YAML ↔ TOML Converter

Convert between formats, pretty-print, minify & validate

CSV / JSON / XML Converter

Paste CSV → JSON or XML · Paste JSON → CSV · Smart column detection

Unix Timestamp Converter

Convert timestamps ↔ human dates, timezone support, ISO 8601 output

Current Unix Timestamp
UTC Time

Regex Tester & Explainer

Live regex with match highlighting, group capture & plain-English explanation

/ /
Matches will be highlighted here…

Text / Code Diff Checker

Side-by-side or unified diff · character, word, or line granularity

Cron Expression Builder

Visual cron builder · next 10 run times · plain-English explanation

MINHOURDOMMONDOW

Lorem Ipsum Generator

Paragraphs, sentences, words or lists — Lorem Ipsum & Hipster variants

Markdown Preview & Editor

Live split-pane editor with GitHub Flavored Markdown · export to HTML

CSS Gradient Generator

Visual linear, radial & conic gradient builder · copy as CSS or Tailwind

Box Shadow & Filter Builder

Visual CSS box-shadow builder with layer stacking & live preview

OG Image & Meta Card Preview

Preview how any URL looks on Twitter/X, Facebook & LinkedIn

Favicon Generator

Upload any image → get .ico, 16×16, 32×32, 48×48, 192×192, 512×512 PNGs + HTML snippet

HTTP Response & Headers Inspector

Inspect status codes, headers, redirect chain & response body

Page Speed & Core Web Vitals

Analyze LCP, CLS, FID/INP, TTFB via Google PageSpeed Insights · mobile + desktop

Readability & Content Analyzer

Flesch-Kincaid, Gunning Fog, SMOG score & word frequency heatmap

Advanced Word & Character Counter

Reading time, speaking time, top keywords & sentence complexity

Characters
0
No Spaces
0
Words
0
Sentences
0
Paragraphs
0
Lines
0
Read Time
Speak Time

Google Admin Toolbox

Official Google tools for DNS, email, browser debugging & more.

Open Toolbox