Development
Render a URL at multiple viewport widths and inspect screenshots, pixel-difference heatmaps, and layout metrics in the page.
responsive-breakpoint-diffMath & Numbers
Calculate the elastic section modulus W = I/y_max and associated geometric properties. Supports rectangle, solid circle, hollow tube, and I-beam; computes I, distance c, area A, and radius of gyration r. Units in mm.
section-modulus-calculatorMath & Numbers
Calculate the infinite-slope factor of safety: FS = c'/(γ·z·cosβ·sinβ) + tanφ'/tanβ. Supports dry slopes and seepage parallel to the slope. Returns FS and a stable/marginal/unstable classification.
slope-stability-calculatorMedia
Edit subtitle timing, shift cues, repair overlaps, calibrate CPS, wrap long lines, and export SRT, VTT, ASS, or TTML.
srt-vtt-subtitle-editorMath & Numbers
Calculate active, reactive, and apparent power for a balanced three-phase system: S=√3·U·I, P=√3·U·I·cosφ, Q=√3·U·I·sinφ. Also returns the power-factor angle φ and verifies the power triangle.
three-phase-power-calculatorMath & Numbers
Calculate the Rankine active earth pressure on a smooth vertical wall backfilled with cohesionless soil. K_a = tan²(45°−φ/2). Optional uniform surcharge q. Returns the base pressure p₀, the total force P, and the resultant height.
active-earth-pressureDevelopment
Convert a cURL command into a portable HAR 1.2 request entry.
curl-to-har-converterMath & Numbers
Calculate the total cross-sectional area of reinforcing steel: A = n·π·D²/4. Choose a standard metric diameter (6–40 mm) or a custom diameter and the number of bars. Also returns the single-bar area, perimeter, theoretical unit weight (ρ=7850 kg/m³), and total weight.
rebar-area-calculatorMath & Numbers
Calculate the maximum shear stress τ_max = V·Q/(I·b) at the neutral axis of a beam section. Supports rectangle (1.5V/A), solid circle (4V/3A), hollow tube, and I-beam (exact V·Q_web/(I·tw)). Also returns the average shear stress V/A for comparison.
shear-stress-calculatorMath & Numbers
Calculate the maximum bending moment M_max, maximum shear force V_max and support reactions for a simply supported beam under a uniformly distributed load, a mid-span point load, or a point load at an arbitrary position. UDL: M_max = qL²/8; mid-span: M_max = PL/4; offset: M_max = P·a·b/L.
simply-supported-beam-calculatorMedia
Clean lecture recordings with speech-focused EQ, hum reduction, peak control, and optional long-silence trimming.
audio-classroom-recording-cleanerMedia
Turn speech phrases into a repeatable practice track with a configurable pause between repetitions.
audio-language-learning-loop-maker