How to Split a Restaurant Bill Fairly (Every Method)
Even split, itemized, one person pays — all 3 bill-splitting methods explained with real math. Includes tip, tax, shared items, and awkward situations.
87 practical guides, cheat sheets, and deep dives for developers, designers, and gamers. No fluff — just the stuff you actually need.
87 posts
Even split, itemized, one person pays — all 3 bill-splitting methods explained with real math. Includes tip, tax, shared items, and awkward situations.
PDF locks layout for sharing; DOCX stays editable for collaboration. Learn which format to use, when to convert, and the most common mistakes.
Every social media image size for 2026 in one place. Covers Instagram, Facebook, X, LinkedIn, TikTok, YouTube, Pinterest, and Threads with pixel dimensions.
Photos embed GPS coordinates, device model, and timestamps in EXIF data. 87% of smartphone photos contain location metadata. Learn how to strip it.
Learn how lossy and lossless image compression work. JPEG quality 80 cuts file size 75% with no visible loss. Real size comparisons and format guide.
Every Markdown syntax element in one reference. Tables, code blocks, task lists, footnotes, and platform differences. Used by 14M+ GitHub repos.
Calculate your BMI instantly with our free online calculator. Learn what BMI means, its categories, limitations, and when to consult a doctor.
Copy-paste cron expressions for every schedule from every-minute to yearly. 20+ ready-to-use examples with plain-English translations and field reference.
Explore the Fibonacci sequence from sunflower spirals to algorithm design. 92% of sunflower heads follow Fibonacci spiral patterns (Royal Society, 2016).
Your IP address exposes your city, ISP, and browsing habits to every site you visit. 76% of websites log IPs. Here's exactly what they see.
Learn how diff works, how the Myers algorithm finds minimal edits, and how to compare text, code, configs, and JSON files in seconds online.
Complete CSS Flexbox and Grid reference with every property, values, and visual examples. 92% of sites now use Flexbox or Grid for layout.
Improve your FPS aim with proven techniques. Covers crosshair placement, eDPI, arm vs wrist aiming, aim trainer routines, and common mistakes to fix first.
Use a spinning wheel picker for fair random selection. Covers classrooms, team meetings, personal choices, and how uniform randomization actually works.
See real mouse polling rate input lag from 125Hz to 8000Hz, what 1000Hz changes, and whether higher rates are worth the CPU cost.
Learn how DPI, eDPI, and cm/360 work together. Pro players average 40-54 cm/360 in tactical shooters. Find your ideal gaming sensitivity with real data.
Complete QR code guide covering error correction levels, minimum print sizes, static vs dynamic codes, and security risks. 2.2B+ QR scans globally in 2025.
Generate secure passwords and passphrases with our free tool. Learn what makes a password strong, how crack time estimates work, and best practices for password security.
UUID v4 is the most widely used identifier format, but RFC 9562 (2024) introduced v7. Learn when to use v1, v4, and v7 for databases and distributed systems.
Visual step-by-step guide to Base64 encoding. See how text becomes a 6-bit alphabet used in data URIs, JWTs, and email. Adds ~33% size overhead.
UTF-8, ASCII, and Unicode explained with byte-level examples. Learn why mojibake happens, how to fix encoding issues, and why UTF-8 powers 98.2% of the web.
Learn when sRGB, Adobe RGB, Display P3, and CMYK matter. Display P3 covers 25% more colors than sRGB. Includes CSS examples and conversion tips.
Remove image backgrounds free in seconds using AI. No signup, no upload. Works for product shots, headshots, logos. Save as transparent PNG or WebP.
Complete unit conversion chart for metric to imperial, temperature, weight, volume, speed, and more. Covers 95% of real-world conversions with exact multipliers.
Need a free WinRAR alternative? Compare 7-Zip, PeaZip, NanaZip, and built-in Windows extraction, plus when WinRAR is still worth paying for.
Reduce image file sizes by up to 80% without visible quality loss. Compare JPEG, PNG, and WebP formats. Step-by-step guide with a free online compression tool.
Every HTTP status code from 1xx to 5xx explained with real-world examples. A developer reference covering all 63 standard codes used by 97% of the web.
Compare PNG, JPG, WebP, AVIF, SVG, and GIF with real file sizes. WebP cuts photo size 25-35% vs JPEG. Find the right format for every use case.
How the world's 24+ time zones work, why UTC and GMT differ, and how DST shifts scheduling. Covers offsets, IANA database, and conversion tips.
Best crosshair settings for CS2, Valorant, and Apex Legends. Covers style, size, color, and pro settings. 73% of top CS2 pros use a static small cross or dot.
The 100 most-used Linux terminal commands with real examples, grouped by task. 97% of servers run Linux (W3Techs, 2025). Bookmark this reference.
Calculate your mortgage monthly payments, total interest, and see a full amortisation schedule. Compare 15, 20, 25, and 30-year mortgage terms.
How TLS handshakes, certificate chains, and HTTPS encryption work step by step. TLS 1.3 cuts handshakes to 1 round trip, down from 2 in TLS 1.2.
Statistics cheat sheet with formulas, worked examples, and when to use mean vs median. 90% of data analysis uses these core measures (ASA, 2024).
Combine PDFs free without watermarks. Gmail caps attachments at 25 MB - large merges routinely hit that. Step-by-step for browser, Mac, Windows, mobile.
Learn binary, octal, decimal, and hex with step-by-step conversions. Over 60% of developer tools rely on hex notation daily. Practical examples included.
20+ battle-tested regex patterns for emails, URLs, phone numbers, IPs, dates, and more. Copy-paste ready with examples for developers.
Real typing speed data by profession and age. The average adult types 40 WPM, but transcriptionists hit 75-100. Full WPM tables and improvement tips.
Find out who owns any domain with WHOIS lookup. Learn what WHOIS data shows, why it's often hidden, how GDPR changed everything, and how to use it for security research.
BMI misclassifies roughly 54 million Americans. Compare BMI to waist-to-hip ratio, body fat percentage, and four other metrics doctors actually use today.
Learn the compound interest formula with real scenarios. $100/month grows to $227,000+ over 30 years. Includes tables, Rule of 72, and calculator.
remove.bg limits free users to low-res previews. These 5 alternatives remove backgrounds for free, including one that runs entirely in your browser.
The best no-watermark Smallpdf and iLovePDF alternatives for compressing, merging, splitting, and converting PDFs without free-tier caps.
SQL cheat sheet with JOIN diagrams, window functions, and query patterns. 70% of developer queries use the same 20 SQL commands (Stack Overflow, 2025).
WebRTC leaks expose your real IP even with a VPN active. 23% of VPN users are vulnerable. Learn how to test and disable WebRTC in every browser.
Learn color harmony rules with real hex values. 90% of snap judgments about products are based on color alone. Build better palettes today.
Visual file size guide: 1 MB holds 500 text pages or 1 compressed photo. Byte to petabyte explained with real-world comparisons and storage planning tips.
Photoshop costs ~$22/month. Most people use 10% of it. Here are the best free alternatives for quick edits, browser tools, and desktop apps.
Learn the mortgage payment formula step by step. See how a $300K loan at 6.5% becomes $1,896/month with real amortization schedules and breakdowns.
MD5 collisions were cracked in 2004. SHA-1 fell in 2017. Here's which hash algorithm is safe today and when to use SHA-256, SHA-512, or BLAKE3.
Find your public IP address instantly. Learn the difference between public and private IPs, how geolocation works, and how to protect your privacy online.
Adobe Acrobat Pro costs $239.88/year. Here are the best free alternatives for merging, compressing, converting, and signing PDFs in 2026.
Adobe Express locks its best features behind a $9.99/month subscription. Here are the best free alternatives for background removal, image resizing, social media graphics, and quick edits in 2026.
Adobe Lightroom costs $9.99/month for 1TB or $19.99/month for Creative Cloud. Here are the best free alternatives for photo editing, RAW processing, and photo management in 2026.
Format, beautify, and minify JSON instantly with our free online tool. Learn about common JSON errors, when to minify vs beautify, and best practices for working with JSON.
See real password crack times by length and character set, from 4 to 20 characters, plus the defenses that actually matter.
Stretched resolution makes models look wider but doesn't change hitboxes. 57% of CS2 pros use 4:3 stretched. Here's what actually changes and whether it helps.
A curated list of the best free browser-based developer tools for 2026. JSON formatters, regex testers, hash generators, UUID tools, and more — all running in your browser.
Learn CIDR notation and subnetting with visual binary breakdowns. Includes a full /8 to /32 cheat sheet covering all 25 prefix lengths and real examples.
Reduce PDF file size by 40-70% without visible quality loss. Learn what makes PDFs large, how compression works, and when not to compress.
Average users click 6-8 CPS. Learn what CPS is, how techniques like butterfly and jitter clicking work, and where click speed actually matters.
Scale recipes for any serving count using the right math. Covers leavening, eggs, spices, cooking time, pan size, and baker's percentages. With a free tool.
Create custom QR codes instantly with our free online generator. Choose colors, sizes, and error correction levels. Perfect for business cards, menus, and marketing.
Master regular expressions with our comprehensive cheat sheet. Test patterns live, learn character classes, quantifiers, lookaheads, and see 10 practical examples.
See average human reaction time by age, when reflexes peak, normal ms ranges, and what actually improves reaction speed.
Learn why WebP is the best image format for the web. Convert PNG and JPG to WebP instantly. Compare file sizes, quality, and browser support across all major formats.
Master D&D 5e ability scores with point buy analysis, class stat priorities, and modifier math. 74% of optimized builds start with a 16 in their primary stat.
DPI vs PPI explained with real pixel math. Learn why 300 DPI matters for print, what PPI means for screens, and how to export images correctly.
Complete git cheat sheet with 50+ commands, real examples, and ASCII branch diagrams. Used by 100M+ developers worldwide. Bookmark this reference.
HEIC files are Apple's photo format since iOS 11 (2017), storing images at half the size of JPEG. Learn why they break on Windows and how to convert them.
Tipping norms by country: US 18-20%, UK 10-15%, Japan no tipping, Australia optional. Covers restaurants, hotels, taxis, and the pre-tax vs post-tax debate.
Master 100+ keyboard shortcuts for Windows, Mac, VS Code, browsers, and Google Docs. Shortcut users save 8 days/year per Brainscape. Full reference.
Learn how to create animated GIFs from a series of images. Covers frame rate, file size, the 256-color limit, and when to use WebP or MP4 instead.
Learn how FOV affects aim, FPS, and motion sickness in shooters. Per-game FOV defaults for CS2, Valorant, Apex. 68% of pros use 100-110 HFOV.
Grammarly Premium costs $12/month. Here are the best free alternatives for grammar checking, spell checking, and writing assistance in 2026 — including tools built into apps you already use.
30+ lorem ipsum alternatives from bacon to baseball. 73% of designers use placeholder text (Adobe, 2024). Find the right generator for your project.
Frame time math for 60Hz to 360Hz monitors with real diminishing returns data. 144Hz cuts frame time by 10ms over 60Hz, and here's what matters for gaming.
How SPF, DKIM, and DMARC work together to stop email spoofing and spam folders. Google now rejects 75% of unauthenticated email from bulk senders.
Learn WCAG contrast ratios with real examples. AA needs 4.5:1 for text, AAA needs 7:1. Fix failing color combos with practical tools and techniques.
Compare API authentication methods with real HTTP examples. OAuth 2.0, JWT, API keys, and session tokens explained. 78% of breaches involve weak auth.
Every DNS record type explained with real dig examples. Covers A, AAAA, CNAME, MX, TXT, NS, SOA, PTR, SRV, and CAA records used across 350M+ domains.
Canva Pro costs $15/month and locks its best templates and AI tools behind the paywall. Here are the best free alternatives for graphic design, image editing, and social media graphics in 2026.
Compare JSON, XML, YAML, and TOML with real config examples. 70% of APIs use JSON (Postman, 2025) - learn which format fits your use case.
Compare mechanical keyboard switches by type, force, travel, and sound. See the chart for Cherry MX, Gateron, Kailh, and the best picks for gaming vs typing.
Brief breaks during focused work maintain near-perfect attention (U of Illinois, 2011). Learn optimal Pomodoro durations and variations for your work type.
Learn probability from basics to Bayes' theorem with real examples. Covers addition and multiplication rules, expected value, and the birthday problem.
Passkeys, authenticator apps, SMS, push, and security keys compared. See phishing resistance, SIM-swap risk, and the best 2FA choice for each account.