Gratis online tools

Free before/after image slider maker — upload two photos, drag the divider to compare, and download a still preview. Fully client-side.

Free rain animation for video — add realistic rain overlays for Reels and export at original resolution. Runs in your browser.

Unlock your password-protected PDF in the browser when you know the password. Download an unprotected copy — free and private.

Decrypt AES-GCM or AES-CBC JSON payloads using the passphrase or hex key that was used to encrypt them.

Free online QML viewer — paste Qt Quick QML to inspect structure and preview layout. Runs entirely in your browser.

Analyze temperature and precipitation climate data. Paste daily or monthly values to get mean, min, max, std dev, heating/cooling degree days, wet days, dry spells, and Northern Hemisphere seasonal summaries (DJF, MAM, JJA, SON). Free, browser-based.

Find the moon phase for any date — new moon, full moon, quarters, and crescents. Shows illumination %, moon age, and days to next new or full moon. Free, browser-based.

Live word, character, sentence, and reading-time statistics.

Find the greatest common divisor (GCD) and LCM of two or more positive integers with Euclidean algorithm steps and prime-factor method.

Predict child blood types from parent ABO and Rh types — Punnett squares, probabilities, and combined outcomes like A+ or O−. Free, instant, browser-based.

Free image to animated wallpaper converter — add breeze, petals, clouds, and sparkle motion to any photo and export for reels. Runs in your browser.

Estimate calories burned during workouts and daily activities from your weight, duration, and activity intensity.