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Free Instagram story/reel safe zone overlay — drop a 9:16 image and preview UI-safe margins for stickers, captions, and CTAs. Client-side only.

Buffer calculator free — Henderson-Hasselbalch pH for acid and base buffers. Solve pH, pKa, or concentrations. Instant, no signup.

Calculate cement, sand, aggregate, and water quantities for concrete mixes. Design by volume, cement bags, or grade presets (M10–M25). Enter mix ratio 1:S:A and water–cement ratio. Metric (m³, kg) and imperial (yd³, lb) units. Free, browser-based.

Calculate gross profit, net profit, profit margin, and markup from revenue, cost, and expenses.

Free online ICO to PNG / SVG icon converter. Convert favicons and icons between ICO, PNG, SVG, WOFF, JPG, WebP, GIF, BMP — plus multi-size packs.

Download public Facebook Reels and short videos as MP4 from facebook.com or fb.watch links.

Free fake tweet generator — create realistic X/Twitter post mockups with metrics, themes, and PNG export. Templates save in your browser only.

Analyze CIDR blocks, convert prefix lengths to subnet masks, split networks, and check whether an IP belongs to a range.

Test regular expressions live against sample text with flags, match details, and replace preview.

Compute symbolic derivatives of functions with step-by-step rules. Supports polynomials, trig, ln, exp, and more.

Free keyboard typing animation maker — cinematic zoom-to-key presses for Reels & YouTube. Export WebM, GIF, MP4, or PNG in your browser.

Calculate sale price, savings, and discount amount from percentage or fixed discounts.