35 free tools for SEO, images, and security
Professional-grade utilities, free forever. Open one and start working. No signup, no watermarks. Fair-use limits apply so the tools stay fast for everyone.
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Checkers
12 toolsRedirect Checker
Trace the full redirect path of any link, hop by hop, with status codes and timing.
SSL Checker
Check any SSL certificate: expiry countdown, issuer, trust status and covered domains.
Bot User-Agent Lookup
Paste a user agent and see if it is a bot, which crawler it is, and what it claims to be.
Security Headers Checker
Grade any site A+ to F on its HTTP security headers, with a fix for every gap.
Meta Tag & OG Checker
Test title, description, Open Graph and Twitter Cards, with a live share preview.
Robots.txt Tester & Generator
Test any robots.txt against real crawlers, or generate one with AI-bot blocking presets.
DNS Lookup & WHOIS
Look up any domain: DNS records, WHOIS registration, expiry and propagation checks.
Website Safety Checker
Check any URL against malware databases and scam red flags before you trust it.
DMARC, SPF & DKIM Checker
Test your email authentication records and generate correct SPF and DMARC in minutes.
Schema Markup Validator
Validate JSON-LD structured data from code or a URL, with rich-result eligibility.
Broken Link Checker
Scan any page for dead links: every 404, timeout and server error, color-coded.
Page Speed Checker
Real Core Web Vitals and a performance score for any URL, with prioritized fixes.
Generators
7 toolsPassword Generator
Cryptographically secure passwords and passphrases, with entropy math and breach checks.
QR Code Generator
QR codes for links, WiFi, vCards and more. Custom colors, logos, SVG export, no expiry.
Favicon Generator
Turn any image, text or emoji into a full favicon set: ICO, PNGs and copy-paste tags.
Invoice Generator
Create a professional invoice in your browser and download it as a PDF. No signup.
WordPress robots.txt Generator
Build a correct WordPress robots.txt with AI-bot blocking presets, without the classic mistakes.
XML Sitemap Generator
Crawl your site and download a ready-to-submit sitemap.xml, with robots.txt respected.
llms.txt Generator
Create a spec-correct llms.txt so AI assistants understand your site, and check any domain.
Image Tools
4 toolsImage Compressor
Compress JPEG, PNG and WebP right in your browser. Nothing is uploaded anywhere.
WebP & AVIF Converter
Convert images to WebP or AVIF in your browser and see the size drop before you save.
Image Converter
Convert between JPG, PNG, WebP and more, in bulk, right in your browser. No uploads.
Image Resizer
Resize images by pixels, percent or presets for WordPress and social. Nothing uploaded.
Developer
3 toolsJSON Formatter & Validator
Format, validate, repair and explore JSON with exact error positions and a tree view.
Base64 Encoder & Decoder
Encode and decode Base64 text and files both ways, with data URIs and image preview.
Color Picker & Converter
Pick any color and convert HEX, RGB and HSL, with shades, contrast and harmonies.
Calculators
5 toolsAmazon Commission Calculator
Project your Amazon Associates earnings by category, price and traffic, with EPC math.
Profit Margin Calculator
Cost and price in, profit, margin and markup out, with fees, quantity and health hints.
Marketplace Fee Calculator
See what eBay, Etsy and PayPal really take from a sale, itemized, with true net profit.
ROI Calculator
Simple and marketing ROI with annualized returns, break-even and sensitivity checks.
Ad Metrics Calculator
CPM, CPC, CTR, CPA and conversion rate from your campaign numbers, with max-bid math.
Text Tools
2 toolsBuilders
1 toolPreviews
1 toolFree tools check once. DevDome watches always.
These tools answer a question right now. DevDome Analytics, Bot Protection and Site Health keep answering it around the clock, on autopilot, for your whole site.