Converters 62 tools

Convert Markdown to HTML in your browser. Live side-by-side editor and preview, copy the HTML, no upload, no tracking.

Shortcut: mthm

Encode and decode base64 with UTF-8 awareness. Paste a string, get base64; paste base64, get the string.

Shortcut: bedb

Convert Unix timestamps to ISO 8601 and RFC 2822, and the other way. Add or subtract seconds, minutes, hours, days.

Shortcut: utct

Convert between common units of length, mass, temperature, time, and data. Live updates, copy to clipboard, swap units in one click.

Shortcut: ucun

Turn text into a clean URL slug. Hyphen, underscore, or dot separator. Stop words, max length, ASCII-only, bulk unique. Live.

Shortcut: slug

Convert between JSON and CSV. Comma, semicolon, tab, or pipe delimiter. Live, RFC 4180, no upload.

Shortcut: jtcc

Add, subtract, multiply, or divide any two fractions, mixed numbers, or decimals in your browser. Live result in mixed, improper, and decimal form, plus a single-input parser and a decimal-to-fraction converter. Pure client-side, no upload.

Shortcut: fcfr

TSV, CSV, JSON, or existing markdown → clean markdown table. Per-column alignment, auto-numeric right-align. Live, in-browser, no upload.

Shortcut: mtgm

Paste a Markdown document and get a Table of Contents back. Markdown list with anchor links, nested HTML, or plain outline. Skips code fences, frontmatter, and HTML comments. Live, in-browser, no upload.

Shortcut: mtoc

Drop an image and get a base64 data URL back. PNG, JPEG, GIF, WebP, SVG, BMP, ICO, AVIF. Pick data URL, CSS url(), or raw base64. Preview, copy, or download. Pure client-side, 10 MiB cap, no upload.

Shortcut: itdu

Resize and re-encode images in your browser. JPEG, WebP, or PNG output; pick a max width and a quality. Side-by-side preview with byte counts and savings ratio. Download, no upload.

Shortcut: icim

Paste a CSV, TSV, or pipe-delimited file and browse it as a table. Auto-detects the delimiter; infers per-column types (number / date / boolean / text); sort, filter, search; copy the filtered view as TSV. Pure client-side, no upload.

Shortcut: cvcs

Type a width and height, get the reduced ratio (1920×1080 → 16:9), preview it as a rectangle, scale to a target dimension, and parse a batch in one go. Common presets (1:1, 4:3, 16:9, 21:9, 9:16) and a lock-ratio toggle. Live, in your browser, no upload.

Shortcut: arca

Drop an image and get the dominant K colours as a palette. Hex / rgb / hsl with population shares, copy each colour, export the whole palette as JSON, CSS variables, SCSS, or TSV. Pure client-side, no upload.

Shortcut: icpe

Paste any CSS colour — hex, rgb(), hsl(), hwb(), or one of 148 named colours — and see it normalised into every other format. Click a chip to copy. Eyedropper support, tint / shade ramp, live preview swatch. Pure client-side, no upload.

Shortcut: cchr

Blend two colors in straight RGB, gamma-corrected RGB linear, HSL (shortest hue arc), or CIE Lab. Pick the step count (2–24), see the gradient as click-to-copy hex swatches, and read the CIE76 ΔE between the endpoints. Pure client-side, no upload.

Shortcut: cmco

Three everyday percentage problems in one tidy tool. Compute X% of Y (e.g. 18% of 84.50 = 15.21), X is what % of Y (e.g. 23 of 80 = 28.75%), and the percent change from X to Y (e.g. 50 → 65 = +30%). Live breakdown, formula, and copy. Pure client-side, no upload.

Shortcut: pcpe

Compute the monthly payment on a fully amortising loan and see the full month-by-month amortisation schedule. Principal, annual rate, term, optional monthly extras and a one-time lump sum. Total interest, payoff date, months and interest saved, copy or download the schedule as CSV. Pure client-side, no upload.

Shortcut: mlcm

Paste a Markdown document and see every link inside it: anchor text, href, line number, kind (http, mailto, tel, anchor, absolute, relative, protocol-relative, file, suspicious javascript:/data:), with one-line lints for empty anchors, missing protocols, and undefined reference ids. Skips fenced and inline code. Copy as TSV or JSON. Pure client-side, no upload.

Shortcut: mlem

Paste HTML (from a CMS, email, Word, or any web page) and get clean Markdown back. Headings, lists, tables, code, blockquotes, embeds handled. Live preview, options for ATX vs setext headings, bullets, and reference links. Pure client-side, no upload.

Shortcut: htmh

Add or subtract years, months, weeks, days, or business days to any date. Or pick two dates and see the gap as calendar y/m/d, total days, weeks + leftover days, and business days. Includes weekday, day-of-year, week-of-month, and ISO 8601 week number for today. Pure client-side, no upload.

Shortcut: dcda

Add or subtract clock durations (1:23:45 + 0:42:18 = 2:06:03). Sum a column of times one per line with per-line error reporting. Convert any of 1:23, 01:23:45, 5m, 2h, 90s, 1d 2h 3m into HH:MM:SS, MM:SS, Dd HH:MM:SS, total seconds, total minutes, and a humanised phrase. Pure client-side, no upload.

Shortcut: tdct

Paste a Markdown document — a README, a blog post, a CMS export — and get the rendered plain text back. Headings, links, images, lists, blockquotes, tables, and code are all unwrapped to plain prose. Configurable code-block handling, list bullet, heading markers, and whitespace. Live, in your browser, no upload.

Shortcut: mtpt

Decode 4, 5, and 6-band resistor colour codes to ohms, tolerance, and temperature coefficient — or type a target resistance and see the colour bands you'd buy across the E6, E12, E24, E48, and E96 series. Live resistor preview, percent-error readout. Pure client-side, no upload.

Shortcut: rccc

Drop or paste an image and see it through the eyes of every common colour-vision deficiency — protanopia, deuteranopia, tritanopia, and achromatopsia. Side-by-side previews, a swatch test row, per-simulation PNG download or a single labelled sheet. Uses the Machado, Oliveira & Fernandes (2009) matrices in linear-light sRGB. Pure client-side, no upload.

Shortcut: cbsc

Translate text to International Morse Code and back, in your browser. Live as you type, dot-and-dash visualizer, copy buttons, prosign support (<SK>, <BT>, <AR>, <KN>, <AS>, <CT>, <KA>), and an A–Z / 0–9 / punctuation / prosign reference. Pure client-side, no upload.

Shortcut: mctm

Drop, paste, or pick any image and see its per-channel histograms — red, green, blue, alpha, and Rec.709 luminance — plus per-channel statistics (mean, median, stddev, min/max, IQR, near-black/white shares). The pixel buffer is sampled at up to 1 MP for bounded memory, all processing is in your browser, no upload.

Shortcut: ihim

Drop, paste, or pick any image and see its full metadata: file name, size, MIME, intrinsic width × height, the reduced aspect ratio (1920×1080 → 16:9), megapixels, alpha channel, format notes, and the colour-space name extracted from any embedded ICC profile (sRGB, Display P3). Live preview, pure client-side, no upload.

Shortcut: imim

Paste a hex value and find the closest matching CSS named colour. CIE76 ΔE in Lab space, top 5 neighbours with verdicts (exact / imperceptible / close / far), click-to-load palette of all 148 named colours, eyedropper support. Pure client-side, no upload.

Shortcut: cnlc

Type a colour temperature in Kelvin and see the matching black-body sRGB colour. Built-in presets (candle, tungsten, daylight, overcast, blue sky), HSL and rgb() readouts, a scene preview, and click-to-copy chips. Pure client-side, no upload.

Shortcut: ctkt

Convert TOML to JSON and JSON to TOML in your browser. Tables, arrays of tables, dotted keys, inline tables, datetimes, hex/octal/binary integers, multi-line strings. Live, no upload.

Shortcut: tjct

Convert YAML to JSON and JSON to YAML in your browser. Block and flow collections, quoted scalars, multi-line strings, anchors and aliases, multi-document streams. Live, in-browser, no upload.

Shortcut: yjcy

Encode and decode base32 using the RFC 4648 standard alphabet (A–Z, 2–7). UTF-8 safe, whitespace-tolerant on decode, positional error reporting, file-friendly with download. Pure client-side, no upload.

Shortcut: badb

Encode and decode base58 in your browser. Three alphabets — Bitcoin (used by Base58Check), Flickr short IDs, and Ripple (XRP). UTF-8 safe, whitespace-tolerant on decode, positional error reporting, live conversion as you type. Pure client-side, no upload.

Shortcut: bsdb

Drop an image and see it rendered as coloured ASCII art in your browser. Width, cell aspect, four character ramps (short / long / binary / blocks), ANSI or HTML output, invert and monochrome toggles, copy or download. Summed-area downsampling keeps results sharp at small widths. Pure client-side, no upload.

Shortcut: itaa

Convert Arabic numbers (1–3999) to Roman numerals and back, bidirectionally. One value per line, live as you type, inline errors, reference tables for the 7 symbols and 6 subtractive pairs, copy and download. Pure client-side, no upload.

Shortcut: rncr

Compute nPr, nCr, n^r (with repetition), and multiset combinations in your browser. BigInt so large values stay exact, comma-separated integer form plus scientific notation for huge counts, copy-ready result, and eight presets (lotto, poker hands, PINs, password lengths). Pure client-side, no upload.

Shortcut: pccp

Project the future value of a savings or investment account. Initial principal, regular contribution (monthly or yearly, end or start of period), annual rate, term, and compounding frequency (annual, semiannual, quarterly, monthly, daily). See the future value, total interest, total contributed, effective annual rate, and a year-by-year schedule. Pure client-side, no upload.

Shortcut: cico

Type an event once and get Add-to-Calendar URLs for Google Calendar, Outlook, and Yahoo, plus a downloadable RFC 5545 .ics file. UTC, local, or any IANA timezone. All-day support, .ics preview, no upload.

Shortcut: elge

Compare two fully-amortising loans side-by-side. Monthly payment, total interest, total cost, effective annual rate, and a verdict that names the cheaper loan. Year-by-year balance chart for visual comparison. Pure client-side, no upload.

Shortcut: lccl

Paste a Markdown draft with <<FN:label>> markers and a list of definitions, get the same Markdown back with footnote references in place and a Footnotes section appended. Three reference styles (numeric, named, user-label) and three output styles. Skips markers inside code fences and inline code. Live, in your browser, no upload.

Shortcut: mfgm

Rewrite any Markdown document into GitHub, Obsidian, and Hugo compatible callouts ([!NOTE], [!TIP], [!WARNING], …). Seven admonition types, auto-detect plain-text hints (Note:, Tip —, Importante:, Wichtig:, …) or stay explicit-only. Live preview, copy or download as .md, idempotent on a second pass. Pure client-side, no upload.

Shortcut: mcgm

Paste a Markdown checklist and get a live, sortable, filterable view with progress and one-click rebuild. Toggle checkboxes in place, sort by status or text, filter to open / done only, copy or download as Markdown. Pure client-side, no upload.

Shortcut: mdgm

Convert text to a binary string and back in your browser. Five separator modes, UTF-8 aware, line-wrap option, live counts. Pure client-side, no upload.

Shortcut: btcb

Paste a list of shift rows (day, start, end, optional break and label) and see daily and weekly totals with overtime against a configurable daily and weekly threshold. Live, in your browser, no upload.

Shortcut: tchc

Estimate the fuel or electricity cost of any road trip. Six consumption units (L/100km, mpg US/UK, km/L, mi/kWh, km/kWh), eight price units (USD/EUR/GBP per L, per kWh, per gallon), multi-stop, round-trip. Live, in your browser, no upload.

Shortcut: fcat

Add or remove VAT, GST, or sales tax from any amount. Country presets seed the rate and currency, composite rates for state/city tax, bulk mode processes one amount per line, three rounding modes (half-up, banker's, truncate). Live, in your browser, no upload.

Shortcut: tvgc

Count business days in a date range. Custom weekend convention (Mon-Fri default plus Fri-Sat, Sun-Thu, Thu-Fri presets or a custom set of weekdays), per-year or recurring MM-DD holiday list, Nth workday picker, and a full workday breakdown. Pure client-side, no upload.

Shortcut: wcwo

Compute the great-circle distance between two latitude/longitude pairs with the haversine and Vincenty (WGS-84) formulas, the initial compass bearing, and the geographic midpoint. Switch units (km, mi, nm, m), pick a city preset, batch a list of points to see leg distances. Live, in your browser, no upload.

Shortcut: gdcg

Compute area, perimeter, surface area, and volume for nine common shapes — square, rectangle, circle, triangle, cube, cuboid, sphere, cylinder, cone. Eight length units (mm, cm, m, km, in, ft, yd, mi), live recompute, diagonals, slant heights and great-circle circumference where they apply, copy-ready summary. Pure client-side, no upload.

Shortcut: gcge

Convert kitchen measurements between US customary and metric. Volume (cup, tbsp, tsp, fl oz, mL, L, pint, quart, gallon), weight (oz, lb, g, kg), length (in, cm), and oven temperature (°C, °F, K) with a UK gas-mark reading. Fraction shorthand (1 1/2) supported. Pure client-side, no upload.

Shortcut: cuco

Convert between watts, kilowatts, megawatts, horsepower (mechanical / electrical / metric), BTU/h, BTU/min, ft-lbf/s, ft-lbf/min, erg/s, cal/s, kcal/h in your browser. 15 NIST SP 811 units grouped SI, horsepower, heat-rate, mechanical, CGS / thermal. Round-trip stable, live, no upload.

Shortcut: pucp

Convert between pascals, hectopascals, megapascals, gigapascals, millibars, bars, atmospheres (atm, at), psi, mmHg, cmHg, inHg, Torr, mmH2O, inH2O in your browser. 16 NIST SP 811 / IUPAC units grouped SI, bar, atmosphere, imperial, mercury, water. Round-trip stable, live, no upload.

Shortcut: prcp

Convert between bits, bytes, KB, KiB, MB, MiB, GB, GiB, TB, TiB, PB. SI (1000) and IEC (1024) conventions. Bulk list, copy. No upload.

Shortcut: dscd

Build a colour palette and get the N×N WCAG 2.x contrast-ratio matrix with per-cell AA / AAA verdicts, the strongest and weakest pair, and a ranked list of every passing pair. Hex, rgb(), hsl(), and 148 named colours. Click-to-copy swatches, copy matrix as TSV. Pure client-side, no upload.

Shortcut: ccmc

Walk a credit-card balance month by month under a fixed payment. Months to payoff, total interest, payoff date, and a year-by-year schedule. Optional extra monthly payment and one-time lump sum with a side-by-side comparison. Detects the minimum-payment trap. Pure client-side, no upload.

Shortcut: ccpc

Convert between US men's / women's / kids', UK, EU, JP, and Mondopoint shoe sizes. From foot length (cm or inches) or from a typed size in any system. Bulk mode with TSV / JSON export. ISO 19407 / Brannock-derived standard table, 21 kids' rows + 28 adult rows. Pure client-side, no upload.

Shortcut: sscs

Plot the normal-distribution bell curve for any mean and standard deviation. Look up P(X ≤ x), z-scores, percentiles, the 68-95-99.7 empirical rule, confidence intervals for the mean, and bulk-sample N(μ, σ). Pure client-side math, no upload.

Shortcut: bcnd

One-way ANOVA in your browser. F-statistic, p-value, decomposition table, per-group means and SDs, η² and ω² effect sizes. Pure client-side math, no upload.

Shortcut: owac

Convert any CSS colour (hex, rgb(), rgba()) into OKLCH and Oklab — CSS Color 4's perceptually-uniform spaces. Live L, C, H editor, 5-step lightness ramp, 5-stop hue ring, sRGB gamut readback, click-to-copy chips for hex / rgb / oklch / lab. Pure client-side, no upload.

Shortcut: hrto

Four pricing moves in one place: discount a list price, mark up a cost to set retail, check the margin on a price you've already chosen, or model the full e-commerce chain (cost → markup → sale → shipping → tax). Shows what the customer pays and what the merchant nets. Pure math, in your browser, no upload.

Shortcut: dmmc

Shift SRT or WebVTT subtitle timestamps by a millisecond offset to fix out-of-sync files. Auto-detect format, optional from-cue index, copy or download. Pure client-side, no upload.

Shortcut: ssub