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Calculators, numerics, date logic, statistics, and finance tools
Image, audio, and video processing, conversion, and optimization tools
Color, layout, graphics, visual styling, and design helper tools
Writing, cleanup, formatting, extraction, and text analysis tools
Format, file, archive, unit, and encoding conversion tools
Developer utilities, networking, web debugging, and automation helpers
AI Tools
Transcribe speech from audio (wav/mp3/m4a/flac/ogg/webm/aac) to text, SRT, VTT or JSON using the grok-stt AI model. Up to 10 minutes.
AI-powered image content safety detector using NSFWJS to classify potentially inappropriate content with fallback analysis, supporting GIF/Animated WebP/APNG and JPEG/PNG/WEBP.
Math & Numbers
Convert moment of force (torque) between newton-metre (N·m, SI base), dyne-centimetre (dyn·cm, CGS = 10⁻⁷ N·m), pound-foot (lbf·ft = 1.3558179483314004 N·m), and kilogram-force-metre (kgf·m = 9.80665 N·m). Each factor is the exact product of the matching force factor and length factor. Converts via N·m to the target unit and lists all four equivalents. Reference: wheel-nut tightening torque ≈ 100 N·m, passenger-car engine peak torque ≈ 250 N·m.
Convert radioactivity (radionuclide activity) between becquerel (Bq, SI base = 1 decay/s), kilo/mega/gigabecquerel, curie (Ci = 3.7×10^10 Bq, exact 1950 ICRU definition, originally the activity of 1 g of radium-226), milli/microcurie, and disintegrations per minute (dpm = 1/60 Bq, exact). Converts via becquerel to the target unit and lists the equivalent value in all eight units. Reference: banana (K-40) ≈ 15 Bq, smoke detector (Am-241) ≈ 37 kBq = 1 µCi.
Health
Estimate the average steady-state plasma concentration under repeated fixed-interval dosing: Css,avg = (F · Dose) / (CL · τ), where F is bioavailability (1 for IV, <1 for oral), CL is clearance, and τ is the dosing interval. If t½ and Vd are also provided, computes the one-compartment IV-bolus accumulation index Rac = 1/(1-e^(-kτ)), peak Cmax,ss, trough Cmin,ss, and time to ~94%/~97% of steady state (4/5 half-lives). Valid only for linear pharmacokinetics with fixed dose and interval — NOT for Michaelis-Menten drugs or non-linear kinetics. Not medical advice.
Convert illuminance between lux (lx = lm/m², SI base), kilolux (1 = 1000 lx), footcandle (1 = 10.7639104 lx), phot (1 = 10000 lx), and nox (1 = 0.001 lx). Converts via lux to the target unit and lists the equivalent value in all five units for reference. Reference values: full moon ≈ 0.25, office lighting ≈ 300–500, overcast day ≈ 1000, direct sunlight ≈ 100000 lux.
Convert luminance between cd/m² (nit, SI base), stilb (1 = 10000 cd/m²), cd/ft² (1 = 10.76391 cd/m²), foot-lambert (1 = 3.426263 cd/m²), apostilb (1 = 0.31831 cd/m²), lambert (1 = 3183.099 cd/m²), and millilambert (1 = 3.183099 cd/m²). All non-SI units except stilb carry a 1/π factor from Lambertian diffuse-emission assumptions. Reference values: LCD display ≈ 200–300, comfortable eye level ≈ 1000, sun surface ≈ 1.6×10⁹ cd/m².
Convert luminous intensity between candela (cd, SI base, = 1/683 W/sr at 540 THz), millicandela (1 = 0.001 cd), and candlepower (1 = 0.981 cd, obsolete standard candle). Converts via candela to the target unit and lists the equivalent value in all three units for reference. Reference values: indicator LED ≈ 5–20 mcd, flashlight ≈ 100–1000 cd, car headlight high beam ≈ 75000 cd.
PDF Tools
Sign PDFs with a PKCS#12 certificate using an ETSI CAdES detached signature.
Permanently remove PDF text and hidden page objects by rebuilding an image-only PDF.
Convert radiation absorbed dose between Gy (gray = J/kg, SI base), kGy (1 = 1000 Gy), cGy (1 = 0.01 Gy), mGy (1 = 0.001 Gy), and rad (1 = 0.01 Gy). Converts via Gy to the target unit and lists the equivalent value in all five units. ⚠️ Absorbed dose is NOT equivalent dose: converting Gy → Sv requires multiplying by the radiation weighting factor w_R (X/γ/β = 1, neutrons 5–20, alpha 20) — use the dose-equivalent converter for that side. Reference values: chest X-ray ≈ 1e-4, CT scan ≈ 1e-2, radiotherapy fraction ≈ 2, whole-body LD50/60 ≈ 4–6 Gy.
Convert radiation equivalent dose between Sv (sievert, SI base), mSv (1 = 0.001 Sv), µSv (1 = 1e-6 Sv), rem (1 = 0.01 Sv), and mrem (1 = 1e-5 Sv). Converts via Sv to the target unit and lists the equivalent value in all five units. ⚠️ Equivalent dose is NOT absorbed dose: equivalent dose = absorbed dose (Gy) × radiation weighting factor w_R (X/γ/β = 1, neutrons 5–20, alpha 20). Converting Sv → Gy requires dividing by w_R — use the absorbed-dose converter for that side. Reference values: natural background ≈ 3 mSv/yr, chest CT ≈ 7 mSv, annual occupational limit ≈ 50 mSv/yr, ARS threshold ≈ 1 Sv.