Toolzer Guides
Long-form, citable reference articles on networking, web protocols, DNS, and security. Every guide is maintained, sourced, and freely reusable — link to any of them from your documentation, blog post, or Stack Overflow answer.
IPv4 vs IPv6: Complete Comparison
Address space, header format, security, NAT, adoption rates — every meaningful difference between the two IP protocols in one table.
Read the guideWebHTTP Status Codes: The Complete Reference
Every HTTP status code (1xx → 5xx) with what it means, when servers send it, and how clients should react. Includes real-world examples.
Read the guideDNSDNS Record Types Explained
A, AAAA, CNAME, MX, TXT, NS, SOA, PTR, SRV, and CAA records — what each one does, when to use it, and how it appears in a zone file.
Read the guideSecurityPassword Security: Modern Best Practices
NIST 2024 guidance, password entropy math, cracking-time tables, 2FA, passkeys, and password managers — what actually keeps accounts safe today.
Read the guideSecurityVPN vs Proxy: Security, Speed & Encryption
Side-by-side comparison of VPNs and proxies — encryption, speed, IP masking, detection, and when each one is the right tool.
Read the guidePDFHow to Convert PDF to Word — 3 Free Methods
Three free ways to convert PDF to editable Word, including OCR for scanned documents. Formatting tips and privacy trade-offs.
Read the guideImagesJPG vs PNG vs WebP: Which to Use When
Compression, transparency, browser support, and file-size trade-offs for the three most common web image formats.
Read the guideSecurityHow Strong Should My Password Be in 2026?
Length vs complexity, NIST 2024 guidance, cracking-time tables, and why passkeys are winning.
Read the guideEncodingWhat Is a QR Code? A Complete Guide
How QR codes encode data, error correction levels, static vs dynamic, security risks, and design tips that scan reliably.
Read the guideDeveloperRegex Cheatsheet — Complete Reference
Character classes, quantifiers, anchors, groups, lookaround, and copy-paste patterns for email, URL, IP, dates, and more.
Read the guideFinance · ARاتجاهات أسعار الذهب في مصر — تحليل 10 سنوات
تحليل شامل لأسعار الذهب في مصر: العوامل المؤثرة، الاتجاهات التاريخية، ونصائح الشراء والبيع.
Read the guidePDF · How-toHow to Merge PDF Files Online — Complete Guide (2026)
Combine PDFs safely in your browser — no upload, no signup. Reordering, quality, and privacy trade-offs.
Read the guideImages · How-toHow to Compress Images Without Losing Quality
Formats, quality settings, resizing, and a browser-based workflow that hits small file sizes without visible artifacts.
Read the guideQR · How-toHow to Create a QR Code for Free — Step by Step
Generate a scannable QR code in seconds. Error correction, print sizes, logo overlays, and static vs dynamic.
Read the guideSecurity · How-toHow to Check if Your Password Has Been Leaked
Safely check breach exposure with k-anonymity. What leaks mean, and exactly what to do if your password appears.
Read the guideImages · How-toHow to Convert HEIC to JPG on Any Device
Convert iPhone HEIC photos on Windows, Mac, mobile, or in-browser. Quality tips, EXIF privacy, batch conversion.
Read the guideNetworking · How-toHow to Test Your Internet Speed Accurately
Wired vs Wi-Fi, ping and jitter, when to blame the router vs the ISP, and how to read speed-test numbers.
Read the guideDeveloper · How-toHow to Format JSON — A Developer's Guide
Prettify, minify, validate. Common syntax errors, comparison tools, and command-line workflows for daily JSON work.
Read the guideAbout these guides
Toolzer publishes these reference articles to complement our free browser tools. Each one is written by practitioners, reviewed for technical accuracy, and updated when the underlying standards change (RFCs, NIST publications, IANA registries). You're welcome to quote, screenshot, or link to any section — a backlink to the original page is the only thing we ask in return.