Home / Guides
Guides
Practical how-to content connected to Serpgy tools.
- How to Compress Images Without Losing Quality — Learn the basics of image compression and practical file-size reduction.
- How to Format and Validate JSON — Understand formatting, validation and minification for JSON work.
- How to Calculate a Percentage — Simple formulas for discounts, increases and ratios.
- How to Write Better SEO URL Slugs — A practical approach to short, readable URLs.
- How to Resize Images for Websites — Choose useful dimensions without shipping oversized files.
- How to Create a Strong Password You Can Actually Use — Length, randomness and passphrases: what really makes a password hard to crack.
- How to Convert Images Between JPG, PNG and WebP — Pick the right format, keep transparency and avoid quality loss when converting.
- How to Create a QR Code That Scans Every Time — Make QR codes for links, text and Wi-Fi, with contrast, size and testing tips.
- How to Check Color Contrast for Accessibility — Understand WCAG AA and AAA ratios and fix text that is hard to read.
- How to Calculate Profit Margin and Markup — Learn the difference between margin and markup and price for the profit you want.
- How to Add or Remove GST and VAT Correctly — Formulas for adding tax to a price and extracting it from a total.
- How to Calculate a Loan EMI — See how the monthly instalment is worked out and how term and rate change the cost.
- How to Create a robots.txt File — Control crawler access, add your sitemap and avoid the mistakes that hide a site.
- How to Write Meta Titles and Descriptions — Write clear search snippets and preview them before you publish.
- How to Decode and Understand a JWT — Read the header, payload and expiry of a token, and why decoding is not verifying.
- How to Write Cron Expressions for Scheduled Jobs — The five cron fields, common schedules and the gotchas that trip people up.
- How to Combine Images into a PDF — Turn photos and scans into one tidy PDF with the right page size and order.