https://55k6.com/en/guides/ Practical bilingual guides from Lite Tools: PDF, images, encoding, passwords and more. en Mon, 02 Nov 2026 11:04:00 GMT https://55k6.com/en/guides/id-photo-sizes-guide/ https://55k6.com/en/guides/id-photo-sizes-guide/ Sun, 01 Nov 2026 16:00:00 GMT Size charts in millimeters and pixels for common ID photos, background color guidance, and a checklist for shooting your own photo so it passes review. https://55k6.com/en/guides/cron-cheatsheet-guide/ https://55k6.com/en/guides/cron-cheatsheet-guide/ Sun, 01 Nov 2026 16:00:00 GMT Field semantics, 14 example expressions, and special character notes, plus the traps: day OR day-of-week, missing 31sts, time zones, DST shifts. https://55k6.com/en/guides/unit-conversion-guide/ https://55k6.com/en/guides/unit-conversion-guide/ Mon, 14 Sep 2026 16:00:00 GMT Conversion tables for length, weight, temperature and data size, the kB vs KiB trap, and how to handle precision. https://55k6.com/en/guides/text-productivity-guide/ https://55k6.com/en/guides/text-productivity-guide/ Thu, 10 Sep 2026 16:00:00 GMT Three ways to dedupe lines, sorting workflows, capitalization rules, word-count uses, and character-level diffing. https://55k6.com/en/guides/health-metrics-guide/ https://55k6.com/en/guides/health-metrics-guide/ Sun, 06 Sep 2026 16:00:00 GMT How BMI is calculated, its limits, basal metabolic rate, activity multipliers, and sensible calorie strategies. https://55k6.com/en/guides/timezone-guide/ https://55k6.com/en/guides/timezone-guide/ Sun, 30 Aug 2026 16:00:00 GMT UTC offsets, daylight-saving pitfalls, Unix timestamps, and practical scheduling tips for distributed teams. https://55k6.com/en/guides/local-privacy-guide/ https://55k6.com/en/guides/local-privacy-guide/ Sun, 23 Aug 2026 16:00:00 GMT Where online tools leak data, how in-browser processing works, which files never to upload, and how to verify it yourself. https://55k6.com/en/guides/json-beginner-guide/ https://55k6.com/en/guides/json-beginner-guide/ Sun, 16 Aug 2026 16:00:00 GMT JSON syntax rules, nesting, a table of the ten most common parse errors, and JSON vs XML vs CSV. https://55k6.com/en/guides/developer-encoding-guide/ https://55k6.com/en/guides/developer-encoding-guide/ Sun, 09 Aug 2026 16:00:00 GMT Percent-encoding rules, how Base64 works, JWT structure and claims, plus debugging tips for all three. https://55k6.com/en/guides/password-security-guide/ https://55k6.com/en/guides/password-security-guide/ Sun, 02 Aug 2026 16:00:00 GMT What makes a password strong, how entropy works, management strategies, hashing basics, and common mistakes. https://55k6.com/en/guides/qr-code-guide/ https://55k6.com/en/guides/qr-code-guide/ Sun, 26 Jul 2026 16:00:00 GMT How QR codes work, sizing rules, error-correction levels, print tips, and static vs dynamic codes. https://55k6.com/en/guides/color-accessibility-guide/ https://55k6.com/en/guides/color-accessibility-guide/ Sun, 19 Jul 2026 16:00:00 GMT How contrast ratios work, what AA/AAA require, common failing color pairs, and a step-by-step checking workflow. https://55k6.com/en/guides/image-format-guide/ https://55k6.com/en/guides/image-format-guide/ Sun, 12 Jul 2026 16:00:00 GMT Lossy vs lossless, quality sweet spots, transparency, and a decision table for picking the right image format. https://55k6.com/en/guides/pdf-guide/ https://55k6.com/en/guides/pdf-guide/ Sun, 05 Jul 2026 16:00:00 GMT How to merge, split and convert images to PDF online — steps, common issues, and why local processing protects your files.