A curated directory of 53 free online tools — calculators, encoders, decoders, generators, and writing tools. Same design philosophy across the whole network.
crontabsheet.com is part of a network of free, single-purpose online tools. Every site shares the same design philosophy: focused, fast, privacy-friendly, no signup, no upsell, no anti-adblock pop-ups.
Calculate square footage for rooms, floors, walls, and land. Supports rectangles, triangles, circles, and irregular shapes. Free and instant.
Calculate percentages, percentage change, percentage difference, and more. Multiple calculation modes for everyday and professional use.
Calculate exact age in years, months, days, hours, and minutes from any date. Find the difference between two dates instantly.
Decode Base64-encoded strings and files instantly in your browser. Supports standard and URL-safe Base64. No data sent to servers.
Encode text or files to Base64 format instantly. Supports standard and URL-safe Base64 encoding. Free and client-side.
URL encode and decode strings, query parameters, and full URLs. Handles all special characters and Unicode. Essential developer tool.
Check the strength of any password instantly. Get detailed analysis, crack time estimates, and improvement suggestions. 100% client-side.
Count words, characters, sentences, paragraphs, and reading time as you type. Useful for essays, blog posts, social media captions, and SEO content.
Free online UUID generator — v1, v4, v5, v7, GUID & Nil UUID. RFC 9562 compliant. No tracking, no logs. All generation happens in your browser.
Format, validate, minify, and convert JSON in your browser. Pretty-print messy JSON, spot syntax errors with line numbers, and switch between JSON, YAML, CSV, and XML.
Generate MD5, SHA-1, SHA-256, SHA-512 and other cryptographic hashes from any text or file. Useful for integrity checks, password hashing demos, and developer testing.
Convert between Unix epoch timestamps and human-readable dates. Supports seconds, milliseconds, and microseconds. Time zone aware.
Repeat any word, phrase, emoji, or sentence up to 100,000 times. Eight specialty tools for WhatsApp messages, emoji walls, stress-test data, Lorem Ipsum, and more.
Work hours and timesheets — hours between times, weekly totals, overtime pay, time between dates, and 50+ time zones. No signup.
Engineering and scientific unit converter with printable reference tables — wire gauges, drill bits, thread specs, pipe sizes, and more.
Convert between profit margin and markup, find break-even, and factor in platform fees, shipping, and tax. With multi-product comparison.
Dimensional (billable) shipping weight for FedEx, UPS, USPS, DHL and 13 more carriers. Compare actual vs volumetric weight with 2026 divisors.
Calculate the volume of a box from its length, width, and height in any units. Cubic feet, inches, meters — for shipping, storage, and packing.
Parcel length-plus-girth against carrier size limits, plus body circumference measurements for fitness tracking. Two calculators in one.
Free, unbiased solar and off-grid calculators — system sizing, savings and payback, battery banks, and country-specific incentive rules.
Calculate, split, and visualize subnets. IPv4/IPv6, VLSM planner, cloud-aware reserved IPs (AWS, Azure, GCP), and Terraform export.
Network and broadcast addresses, usable host range, wildcard masks, and VLSM planning for IPv4 and IPv6. Cloud-aware, with a learn center.
Build, test, and debug regular expressions with token-by-token plain-English explanations, a pattern library, and code in 7 languages.
Convert text between Title Case (AP, Chicago, APA, MLA), sentence case, camelCase, snake_case, kebab-case, and more. Side-by-side preview.
35+ browser-based image tools — compress, convert, resize, crop, and watermark. JPG, PNG, WebP, AVIF, HEIC. Files never leave your device.
Online alarm clock, timer, stopwatch, and world clock that runs in your browser. Alarms ring even with the tab in the background.
Strip EXIF, GPS, and hidden metadata from images, PDFs, and Office files — locally in your browser, with a pre-strip inspector.
EMI calculator for home, car, and personal loans in India. Full amortization schedule, prepayment impact, and total interest breakdown.
Find the total interest paid over the life of any loan. Compare terms and rates with a full amortization schedule.
Project mutual-fund SIP returns, step-up SIPs, and goal-based investing. Maturity value and wealth-gain breakdown with charts.
Compute semester and cumulative GPA on 4.0 and weighted scales. Convert letter grades and percentages, and plan target grades.
Add, subtract, multiply, and divide fractions with step-by-step working. Simplify, convert to decimals, and find common denominators.
Estimate daily calorie needs, TDEE, and macros from your goals. BMR-based targets for weight loss, maintenance, and gain.
Calculate BMI, BMR, and daily calorie needs in one place. Metric and imperial, with healthy-weight ranges and activity factors.
Size an air conditioner by room area, climate, and occupancy. Get BTU and tonnage estimates for homes and offices.
Volume and fill level for cylindrical, rectangular, and oval tanks. Horizontal or vertical, in litres or gallons.
Calculate cubic yards for concrete, mulch, gravel, soil, and sand. Enter dimensions in any units and get material quantities.
Calculate pool volume in gallons or litres for rectangular, round, and oval pools. Dosing help for chlorine and chemicals.
Estimate concrete volume plus cement, sand, and aggregate quantities. Slabs, footings, columns, and bags needed by mix ratio.
Calculate roofing squares, shingle bundles, and underlayment from area and pitch. Waste factor and material estimates included.
Work out stair rise, run, stringer length, and headroom to code. Diagram output for carpentry and deck building.
A hub of construction calculators — concrete, framing, drywall, paint, and more. Material estimates and quantities for any job.
Calculate voltage drop and correct wire size for AC and DC circuits. NEC and IEC formulas with copper and aluminium conductors.
Size an off-grid battery bank from your daily load, autonomy days, and depth of discharge. Lead-acid and lithium presets.
Estimate UPS and generator runtime from your load and battery capacity. Size backup power for home, office, and server racks.
Convert cooking measurements between cups, grams, ounces, and millilitres. Ingredient-aware conversions and recipe scaling.
Convert numbers to words for cheques, invoices, and legal documents. Supports currency wording and multiple number systems.
Merge, split, compress, convert, and rotate PDFs right in your browser. No uploads to a server — files stay on your device.
Pick colors and convert between HEX, RGB, HSL, and CMYK. Build palettes, check contrast, and grab ready-to-paste CSS values.
Generate QR codes and barcodes (Code 128, EAN, UPC, and more). Download as PNG or SVG for print, packaging, and labels.
Test your download, upload, ping, and jitter in the browser. Quick, accurate speed checks with no app to install.
See your public IPv4 and IPv6 address, ISP, and approximate location. Plus headers, user agent, and connection details.
Look up domain WHOIS, registrar, name servers, and expiry dates. DNS records and registration details for any domain.
Each site is focused on one task. A single mega-site with hundreds of tools (like some competitors) ends up cluttered and slow. By splitting tools across focused domains, each site loads fast, ranks well for its specific keywords, and stays easy to navigate.
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