More free tools
CorePDFTools is part of a small network of independent, free, no-nonsense web tools. No sign-ups, no nonsense — just tools that do one job well. Here's the whole family.
Time and dates
For working with timestamps, durations, and calendar math.
Epoch Time Converter
Convert Unix timestamps, ISO 8601, and specialty formats (LDAP, .NET ticks, Chrome, GPS, Excel, Julian Day).
epochtime.tools →Calculate Hours
Precision calculator for hours and minutes worked. Time-tracking math simplified.
calculatehours.net →Age Calculator
Calculate exact age from a birthdate — years, months, days, hours, seconds.
theagecalculator.net →World Clock
Compare times across cities and time zones, and coordinate across regions at a glance.
clockwithus.com →Encoding and decoding
Convert between text and binary formats safely.
Base64 Decoder
Decode any Base64 string to text or files. Auto-detects file types (PNG, PDF, ZIP).
base64decode.tools →Base64 Encoder
Encode any text or file to Base64. URL-safe variant supported.
base64encode.tools →URL Encoder/Decoder
Encode and decode URL-percent strings for API testing and debugging.
urlencodedecode.com →Data, hashing, and security
For developer-style workflows.
JSON Tools
Format, validate, minify, and convert JSON. Compare two documents.
jsontools.tools →Hash Generator
MD5, SHA-1, SHA-256, SHA-512 hashes for any text or file.
hashgenerator.tools →UUID Generator
Generate UUIDs in v1, v4, and v7 formats. Bulk generation.
uuidcore.com →Password Strength Checker
Test how strong a password is against real attack patterns.
passwordstrength.net →Crontab Cheat Sheet
Build and decode cron schedule expressions, with a quick reference for every field.
crontabsheet.com →Regex Guide
Test and learn regular expressions with live matching and a pattern reference.
regexguide.com →CIDR Calculator
Work out IP ranges, host counts and network blocks from CIDR notation.
cidrcalculator.net →Subnet Mask Calculator
Calculate subnet masks, network and broadcast addresses, and usable host ranges.
subnetmaskcalc.net →Remove Metadata
Strip EXIF and hidden metadata from images and files, right in your browser.
removemetadata.tools →Internet Speed Test
Test your download, upload and ping speed right in the browser.
checkinternetspeed.tools →What Is My IP
See your public IP address, location, ISP and browser details.
checkmyipnow.com →WHOIS Lookup
Look up domain registration, ownership, expiry and DNS records.
whoislookuppro.com →Writing and calculators
Practical helpers for everyday tasks.
Word Counter
Count words, characters, paragraphs, and reading time.
wordcounterfree.com →Percentage Calculator
Compute percentages, changes, and differences.
bestpercentagecalculator.net →Square Footage
Calculate area for flooring, paint, real estate.
thesquarefootagecalculator.com →Text Repeater
Repeat any text or string a set number of times, with custom separators.
textrepeat.net →Case Converter
Convert text between upper, lower, title, sentence, camel and snake case.
transformcase.com →Margin vs Markup
Convert between profit margin and markup, and price products correctly.
marginvsmarkup.com →India EMI Calculator
EMI calculators for home, car, personal, education and business loans — built for Indian borrowers. Honest math, no lead-gen.
indiaemi.com →Total Interest Calculator
See the total interest paid over the full life of a loan.
totalinterestcalc.com →SIP Calculator
Project mutual fund SIP returns by rate, tenure and step-up.
sipcalculatorhub.com →Calorie Calculator
Estimate daily calorie needs, BMR and macros for your goals.
calorieskit.com →BMI & BMR Calculator
Find body mass index and basal metabolic rate in seconds.
bmibmrcalc.com →Fraction Calculator
Add, subtract, multiply and divide fractions step by step.
fractionsteps.com →Number to Words
Convert numbers to words for cheques, invoices and documents.
numtotext.com →GPA Calculator
Calculate GPA and CGPA from grades and credit hours.
gpacalculatorhq.com →Math and measurement
Units, volumes, and everyday measurement math.
Unit Cheat Sheet
A quick reference and converter for length, weight, volume and other units.
unitcheatsheet.com →Box Volume Calculator
Calculate the volume of a box from its dimensions, in any unit.
boxvolumecalculator.com →Dimensional Weight
Work out shipping dimensional (volumetric) weight for couriers and freight.
dimweightcalc.com →Girth Calculator
Calculate parcel girth (length plus girth) for shipping size limits.
girthcalculator.com →Solar Calculator
Estimate solar panel output, system size and savings for your setup.
prosolarcalc.com →Voltage Drop Calculator
Calculate voltage drop by wire gauge, length and current.
voltdropcalc.com →AC Tonnage Calculator
Size an air conditioner in tons from room area and climate.
actonnagecalc.com →Tank Volume Calculator
Volume and fill level of cylindrical, oval and rectangular tanks.
tankvolumecalc.com →Cubic Yardage Calculator
Cubic yards of concrete, gravel, mulch and soil for projects.
cubicyardage.com →Pool Volume Calculator
Pool water volume in gallons or litres for any shape and depth.
poolvolumecalc.com →Solar Battery Bank Calculator
Size a solar battery bank by load, autonomy and discharge depth.
solarbatterybankcalc.com →Backup Power Calculator
Size a generator or battery backup by wattage and runtime.
backuppowercalc.com →Cooking Measurement Converter
Convert cups, grams, ounces and spoons for any recipe.
measurechef.com →Stair Calculator
Work out stair rise, run, stringer length and step count.
staircalculators.net →Concrete Material Calculator
Estimate concrete, cement, sand and aggregate for slabs.
concretematerialcalc.com →Roofing Material Calculator
Estimate shingles and materials by roof area and pitch.
roofingmaterialcalc.com →Construction Calculators
A hub of construction calculators for materials and estimates.
constructioncalchq.com →Images and files
Quick image and file utilities that run in your browser.
CorePDFTools
Private, in-browser PDF tools — merge, split, compress, convert, sign and protect. Files never uploaded.
corepdftools.com →Picture Toolkit
Resize, convert and compress images in the browser, with no upload to a server.
pictoolkit.com →Color Code Kit
Pick and convert colours across HEX, RGB and HSL, and build palettes.
colorcodekit.com →Barcode & QR Generator
Generate QR codes and barcodes for URLs, text and products.
barcodeandqr.com →