Free online tools that respect your data

Popular tools

• AI Token CounterEstimate token counts and API cost for GPT, Claude, Gemini and Llama.
• JSON Formatter & ValidatorBeautify, minify and validate JSON with precise error positions.
• Base64 Encoder & DecoderEncode or decode Base64 text, files and data URLs, with UTF-8 support.
• Cron Expression GeneratorBuild, explain and preview cron schedules in plain English.
• Image CompressorShrink JPG, PNG and WebP images in your browser without uploading them.
• Password GeneratorGenerate strong random passwords and passphrases with an entropy readout.
• QR Code GeneratorCreate permanent QR codes for links, text, Wi-Fi and contact cards.
• Regex TesterTest regular expressions live with match highlighting and capture groups.
• Text Diff CheckerCompare two blocks of text and highlight every added and removed line.
• Unix Timestamp ConverterConvert Unix epoch seconds or milliseconds to a human date, and back.
• Word & Character CounterLive word, character, sentence and reading-time counts as you type.
• Age CalculatorWork out an exact age, or the gap between any two dates.
• Case ConverterConvert text between upper, lower, title, sentence, camel, snake and kebab case.
• Chmod CalculatorTick permission boxes to get the octal chmod value, or type a value to see what it grants.
• Color ConverterConvert between HEX, RGB, HSL, HSV, CMYK and CSS named colors.
• Favicon GeneratorTurn an image, letter or emoji into a full favicon set plus the HTML.
• JSON to CSV ConverterConvert JSON arrays to CSV and CSV back to JSON, with nested key flattening.
• JWT DecoderDecode a JWT header and payload, and check its expiry — offline.
• Percentage CalculatorWork out percentages, increases, decreases, discounts and tips.
• Subnet CalculatorEnter an address and prefix to get the network, broadcast, usable range and host count.
• UUID GeneratorGenerate cryptographically random UUID v4, time-ordered v7 and Nano IDs.

Developer Tools

• JSON Formatter & ValidatorBeautify, minify and validate JSON with precise error positions.
• Base64 Encoder & DecoderEncode or decode Base64 text, files and data URLs, with UTF-8 support.
• Cron Expression GeneratorBuild, explain and preview cron schedules in plain English.
• Password GeneratorGenerate strong random passwords and passphrases with an entropy readout.
• Regex TesterTest regular expressions live with match highlighting and capture groups.
• Unix Timestamp ConverterConvert Unix epoch seconds or milliseconds to a human date, and back.
• Chmod CalculatorTick permission boxes to get the octal chmod value, or type a value to see what it grants.
• JSON to CSV ConverterConvert JSON arrays to CSV and CSV back to JSON, with nested key flattening.
• JWT DecoderDecode a JWT header and payload, and check its expiry — offline.
• Subnet CalculatorEnter an address and prefix to get the network, broadcast, usable range and host count.
• UUID GeneratorGenerate cryptographically random UUID v4, time-ordered v7 and Nano IDs.
• Hash GeneratorGenerate SHA-256, SHA-384, SHA-512, SHA-1 and MD5 hashes of text or files.
• Text to BinarySee any text as binary, hexadecimal, decimal, octal and UTF-8 bytes at once.
• URL Encoder & DecoderPercent-encode or decode URLs and query strings, with a parameter breakdown.

Text Tools

• Text Diff CheckerCompare two blocks of text and highlight every added and removed line.
• Word & Character CounterLive word, character, sentence and reading-time counts as you type.
• Case ConverterConvert text between upper, lower, title, sentence, camel, snake and kebab case.
• Markdown to HTML ConverterConvert Markdown to clean HTML with a live side-by-side preview.
• Lorem Ipsum GeneratorGenerate classic or modern placeholder text by paragraph, sentence or word.

Converters

• Age CalculatorWork out an exact age, or the gap between any two dates.
• Color ConverterConvert between HEX, RGB, HSL, HSV, CMYK and CSS named colors.
• Percentage CalculatorWork out percentages, increases, decreases, discounts and tips.
• Number Base ConverterConvert numbers between binary, octal, decimal, hexadecimal and any base.
• Roman Numeral ConverterConvert numbers to Roman numerals and Roman numerals to numbers.

Image Tools

• Image CompressorShrink JPG, PNG and WebP images in your browser without uploading them.
• QR Code GeneratorCreate permanent QR codes for links, text, Wi-Fi and contact cards.
• Favicon GeneratorTurn an image, letter or emoji into a full favicon set plus the HTML.

AI Tools

• AI Token CounterEstimate token counts and API cost for GPT, Claude, Gemini and Llama.

Popular lookups

The specific answers people search for most often.

• 5 feet in cm
• 180 lbs in kg
• 1 kg in lbs
• Inches to cm
• Kilometres to miles
• Celsius to Fahrenheit
• 100°C in °F
• GB to MB
• Minutes to hours
• px to rem
• PST to EST
• UTC to EST
• 1 cup flour in grams
• 1 cup sugar in grams
• #FF0000
• #000000
• HTTP 404
• HTTP 301
• HTTP 500
• Port 3306
• Port 8080
• Port 443
• 2026 in Roman numerals
• 4 in Roman numerals
• A4 paper size
• Letter paper size
• .heic files
• .webp files
• PNG to JPG
• WebP to PNG
• Cron: every 5 minutes
• chmod 755
• chmod 644
• chmod 777
• /24 subnet
• /16 subnet
• /30 subnet
• ASCII 65 (A)
• ASCII 10 (LF)
• ASCII 0 (NUL)

Reference libraries

• Unit converter1,000+ conversions across length, weight, temperature, volume, data, speed and more.
• Color codes600+ HEX colors with RGB, HSL, CMYK, contrast ratios and matching palettes.
• CSS unitspx, rem, em, pt and more — with an adjustable root font size.
• Time zones848 conversions between EST, PST, UTC, CET, IST, JST and more.
• Image convertersPNG, JPG, WebP, SVG, AVIF and HEIC-adjacent formats, converted locally.
• HTTP status codesEvery code explained — what triggers it and how to actually fix it.
• Cron schedulesReady-made expressions for every common schedule, with next run times.
• Port numbersWhat runs on each port, why it matters, and how to see what is listening.
• File formatsWhat each extension is, what opens it, and what catches people out.
• File permissionsWhat every chmod value grants, and which one is actually right.
• CIDR prefixesEvery subnet size from /0 to /32 with masks and host counts.
• ASCII tableAll 128 codes, with the control characters explained rather than blank.
• Cooking conversionsCups to grams per ingredient — a cup of flour and a cup of honey are not the same weight.
• Roman numeralsEvery number broken down symbol by symbol, plus the rules that govern them.
• Paper sizesA4, Letter, Legal and the rest — in mm, inches and pixels at any DPI.
• Screen resolutions1080p, 1440p, 4K and the rest — aspect ratio, megapixels and PPI.
• Screen sizesTV and monitor dimensions in inches and cm, and what a step up really adds.
• Oven temperaturesGas mark, °C, °F and the fan equivalent — and why the numbers are rounded.
• Bed sizesUS, UK and European mattress dimensions — and why the names do not travel.
• Lumber sizesNominal against actual — a 2x4 is 1½ × 3½ inches, and here is every other board.
• Battery sizesDimensions, voltage and equivalents — and why a CR2032 is called that.
• Wire gaugeAWG in mm, area and resistance — and the formula the whole scale comes from.
• Metric threadsTapping drill, clearance hole and spanner size for M2 to M24.
• Tyre sizesWhat 205/55R16 measures, which sizes replace it, and the speedometer effect.
• Ring sizesUS, UK and EU conversion — and why the European size is just the measurement.
• Baking tin sizesArea, volume and which tin substitutes for which — and what it does to the time.
• Paper weightGSM to lb — and why 80 lb text and 80 lb cover are different papers.
• Bedding sizesDuvet and comforter dimensions, and how far each hangs over the bed.
• Shoe sizesUS, UK and EU with the foot length each fits — measure first, convert second.
• Door sizesLeaf, rough opening and clear width — three numbers, only one of them the door.
• Sandpaper gritP grades against CAMI grit — P400 is about 320, and here is the whole chart.
• Spanner sizesMetric against imperial — which pairs swap, and which round a bolt head.
• Pipe sizesNPS, DN and the real outside diameter — a half-inch pipe is 0.84 inches.
• Screw sizesGauge to millimetres, and the two different holes a joint needs.
• Brick sizesFormat, coursing and bricks per square metre — where "sixty" comes from.
• Password lengthWhat each length is worth in bits and in time, and where the useful range ends.
• Knitting needlesUS, UK and mm — two scales that run in opposite directions and meet once.

Why Toolman?

• Private by design. Every tool is pure client-side JavaScript. Your text, code and images never leave your device.
• Fast. Static pages, no frameworks, no trackers. Most tools are usable in under a second.
• Free, forever. No accounts, no paywalls, no watermarks, no daily limits.