home / free tools

Free online tools

A directory of free, private, no-signup tools we build and maintain — calculators, converters, and developer utilities that run in your browser. Nothing uploaded, no account needed.

Like this barcode & QR generator, every tool below is browser-based and free to use. Pick a category and open whatever you need.

Developer & data tools

Encoders, formatters, generators and references for developers.

Base64 Decode / EncodeEncode text or files to Base64 and decode Base64 strings back to their original form. Useful for embedding data in URLs, JSON, data URIs and config files — all processed in your browser.base64decode.tools URL Encode / DecodePercent-encode URLs and query components, or decode encoded strings back to readable text. Handles reserved characters, spaces and unicode so your links and parameters stay valid.urlencodedecode.com UUID GeneratorGenerate universally unique identifiers in bulk, across multiple versions, for database keys, API tokens and distributed systems. Copy one or thousands at a time.uuidcore.com JSON ToolsFormat, validate, repair and explore JSON with a tree view and clear error reporting. Fix broken JSON with 20+ repair rules and read deeply nested data without the headache.jsontools.tools Hash GeneratorCompute MD5, SHA-1, SHA-256 and 30+ other hashes from text or files using a pure-JavaScript engine. Includes plain-language notes on which algorithms are safe to use today.hashgenerator.tools Epoch / Unix Time ConverterConvert Unix timestamps to human-readable dates and back, in seconds or milliseconds, across time zones. A quick reference for logs, APIs and database timestamps.epochtime.tools Crontab Cheat SheetBuild cron schedule expressions visually and decode existing ones into plain English. See exactly when a job will run before you commit it to your server.crontabsheet.com Regex GuideLearn, build and test regular expressions with live matching and clear explanations of each token. A practical reference for both beginners and experienced developers.regexguide.com Password Strength CheckerTest how strong a password really is against common cracking patterns, with feedback on length, entropy and reuse. Checked entirely in your browser — nothing is sent anywhere.passwordstrength.net CIDR CalculatorPlan IP address ranges and subnets from CIDR notation — network, broadcast, usable hosts and mask. Built for network engineers and anyone designing an address scheme.cidrcalculator.net Subnet Mask CalculatorFull IPv4 and IPv6 subnetting with VLSM planning, cloud-native modes and infrastructure-as-code export. A complete toolkit for designing and documenting networks.subnetmaskcalc.net

Text tools

Counting, transforming and repeating text.

Word CounterCount words, characters, sentences and paragraphs in real time, with estimated reading and speaking time. Handy for essays, articles, social posts and meeting scripts.wordcounterfree.com Case ConverterConvert text between UPPERCASE, lowercase, Title Case, Sentence case, camelCase and more in one click. Clean up pasted text or reformat headings and code instantly.transformcase.com Text RepeaterRepeat any word, phrase or line a chosen number of times, with optional separators and new lines. Useful for testing, placeholder content and bulk formatting.textrepeat.net

Calculators

Everyday math, finance, time and measurement.

Square Footage CalculatorCalculate area in square feet or metres for rooms, floors, walls and land — including irregular shapes. Ideal for flooring, painting, tiling and real-estate estimates.thesquarefootagecalculator.com Percentage CalculatorWork out percentages, percentage increase and decrease, and the difference between two numbers. Covers discounts, tips, tax, grades and everyday "what percent of" questions.bestpercentagecalculator.net Age CalculatorFind an exact age in years, months, weeks and days between any two dates, plus upcoming birthdays and milestones. Useful for forms, eligibility checks and planning.theagecalculator.net Hours CalculatorAdd up hours and minutes between start and end times, with breaks, to total a timesheet or work shift. Convert between decimal hours and hours-and-minutes easily.calculatehours.net Box Volume CalculatorCalculate the volume and capacity of boxes and containers from length, width and height, in metric or imperial units. Handy for packing, shipping and storage planning.boxvolumecalculator.com Dimensional Weight CalculatorWork out shipping dimensional (volumetric) weight across 17 carriers so you can predict postage costs before you ship. Compare actual versus billable weight at a glance.dimweightcalc.com Girth CalculatorCalculate package girth for carrier size limits, plus body-measurement girth for fitness tracking. Two related measurements in one clean, private tool.girthcalculator.com Margin vs Markup CalculatorConvert between profit margin and markup, and see how each affects your selling price. Clears up one of the most common pricing mistakes in retail and wholesale.marginvsmarkup.com EMI CalculatorCalculate loan EMIs, total interest and a full amortization schedule for home, car and personal loans. See exactly how much each payment goes to principal and interest.indiaemi.com Solar CalculatorEstimate the solar system size, panel count and potential savings for your energy use and roof. A practical starting point before talking to an installer.prosolarcalc.tools Unit Cheat SheetA quick reference for converting between common units of length, weight, volume, area and temperature. Find the conversion you need without digging through menus.unitcheatsheet.com

Time & clocks

Clocks, time zones and time references.

Clock With UsLive clocks and a clean time-zone reference for checking the current time in cities around the world. Useful for scheduling calls and coordinating across regions.clockwithus.com

Image, PDF & file tools

Private, in-browser file utilities — nothing uploaded.

Image ToolkitCompress, convert, resize and crop images privately in your browser, with optional advanced compression. Your photos never leave your device — nothing is uploaded.pictoolkit.com PDF ToolsMerge, split, reorder and manage PDF files entirely in the browser. Combine documents or pull out pages without uploading sensitive files to a server.corepdftools.com Remove MetadataStrip EXIF, location and other hidden metadata from photos and files before you share them. A simple privacy step that runs locally and reveals what was hidden.removemetadata.tools Color Code KitA developer color toolkit for converting between HEX, RGB, HSL and OKLCH, building palettes and generating design tokens. Everything a designer or front-end dev needs in one place.colorcodekit.com

These are independent sites we build and maintain. Each opens in a new tab.