Free tools that respect your time, your data, your language.

Combine several PDFs into one, in the order you choose. Runs entirely in your browser — nothing is uploaded, so there is no server copy to delete.

Render each page of a PDF to a PNG image at 72, 150 or 300 DPI. Runs in your browser — the document is never uploaded.

Turn JPG, PNG, WebP or GIF photos into a single PDF, one image per page, in the order you choose. Runs entirely in your browser — the photos are never uploaded.

Read the text out of a scanned PDF and either save it as .txt or get the same PDF back with an invisible, searchable text layer. Runs in your browser.

Read the text out of photos and screenshots in English, Vietnamese, Spanish or Portuguese. The recogniser runs in your browser — no image is uploaded.

Shrink a photo to fit an upload limit, with the before and after shown side by side. Runs in your browser — the image is never uploaded.

Scale an image to exact pixels, a percentage, or to fit inside a box. Runs in your browser — nothing is uploaded.

Bundle several files into one .zip, with a compression level you choose. Runs in your browser — nothing is uploaded.

Open a .zip, .7z, .rar, .tar or .tar.gz and pull out the files you need. Runs in your browser — the archive is never uploaded.

Make an EAN-13, EAN-8, UPC-A, ITF-14, Code 128, Code 39, Data Matrix, PDF417 or Aztec code. Check digits verified before encoding; SVG and PNG download. Runs in your browser.

Read QR, Data Matrix, Aztec, PDF417, EAN, UPC, Code 39/93/128 and ITF from a photo or your camera. Lists every code in the image; Wi-Fi codes split into network and password. Runs in your browser.

Extract page ranges from a PDF, or split it into one file per page. Runs in your browser — the document is never uploaded.

Free online Base64 encoder and decoder. UTF-8 safe, works offline, runs entirely in your browser.

Encode and decode URL components per RFC 3986. UTF-8 safe, runs in your browser.

Inspect JSON Web Tokens in your browser. Header, payload, expiry. No key required, no data sent.

Generate UUIDs v4, v7, and v1 in the browser. Sortable v7 recommended for database keys.

Compute MD5, SHA-1, SHA-256, SHA-384, SHA-512 hashes of text or files. Hex or Base64 output. Browser-only.

Generate strong passwords with crypto-grade randomness. Length, charsets, ambiguous-char filter. Browser-only.

Convert between Unix seconds, milliseconds, ISO 8601, and timezone-aware human dates.

Format, minify, sort, and validate JSON. JSON5 mode accepts comments and trailing commas. Browser-only.

Format SQL across 10 dialects (Postgres, MySQL, SQLite, BigQuery, Snowflake, T-SQL, PL/SQL, …). Browser-only.

Test JavaScript regex patterns against any text. Capture groups, named groups, flags, replace mode. Browser-only.

Free BMI calculator with metric + imperial units. Shows category from underweight to obese class III. For estimation only.

Quick tip calculator with bill splitter. Set tip percentage, number of people, see per-person amount instantly.

Calculate exact age in years, months, days, hours, and minutes from a birth date.

Three modes: X% of Y, X is what % of Y, % change from X to Y. Discounts, taxes, grades, growth rates.

Calculate cumulative GPA on the US 4.0 scale. Add courses with grade and credit hours, get weighted average.

Calculate compound interest over time with monthly contributions. See final balance, total interest, total contributions.

HEX ↔ RGB ↔ HSL color converter with WCAG AA/AAA contrast checker. For designers and accessibility audits.

Convert length, weight, temperature, volume, and speed between metric and imperial units.

Pull the images embedded in a PDF at their original resolution — not screenshots of the pages. Runs entirely in your browser.

Stamp page numbers onto a PDF — six positions, three formats, any starting number and any page range. Runs entirely in your browser, so the document is never uploaded.

Stamp text or a logo across the pages of a PDF — choose the size, angle, colour and opacity, and see it on page one before you commit. Runs entirely in your browser.

Convert whole numbers between binary, octal, decimal, hex and any base from 2 to 36. Exact for values above 2^53, where parseInt quietly rounds.

Break a URL into protocol, host, port, path segments and query parameters. Repeated query keys are kept, not collapsed.

Read a User-Agent string into browser, engine, OS and device. Handles the fact that Edge claims to be Chrome and Chrome claims to be Safari.

Convert between Roman numerals and numbers, both directions. Rejects readable-but-invalid forms like IIII and IM.

Generate title, description, Open Graph and Twitter card tags, with warnings for the mistakes that break social previews.

Drag a box to crop, with presets for 1:1, 4:5 and 16:9. Works with a mouse or a touchscreen. Runs in your browser.

Turn PDF pages 90, 180 or 270 degrees — all of them or just the ones you name. Runs in your browser, nothing is uploaded.

Delete pages from a PDF by number or range. Runs entirely in your browser — the document is never uploaded.

Convert text between camelCase, snake_case, kebab-case, PascalCase, CONSTANT_CASE and 8 more. Browser-only.

Turn any text into URL-safe slug. Handles Vietnamese diacritics, German ß, French accents, emoji.

Encode/decode HTML entities (&, <, >, named, numeric, hex). Full HTML5 entity set.

Generate realistic mock data (users, emails, addresses, dates) as JSON, CSV, or SQL. 7 locales.

Convert between JSON, YAML, and TOML. Auto-detect input format. Browser-only.

Convert between CSV and JSON. Auto-detect delimiter, quote handling, header row toggle. Browser-only.

Convert Markdown to HTML and back. GFM (tables, task lists) supported. Browser-only.

Compare two texts character/word/line. Generate unified patch. Browser-only.

Convert curl commands to fetch, axios, Node, Python, PHP, Go. Browser-only.

Parse cron expressions to human language. See next 10 scheduled runs. Browser-only.

Convert a time between IANA timezones. Meeting planner across continents. Browser-only.

Format, minify, and validate XML. Preserves attributes, namespaces, CDATA. Browser-only.

Format, validate and optionally sort the keys of any YAML, with 2- or 4-space indent. Parse errors report the line that broke. Runs in your browser.

Generate placeholder text — classic Lorem Ipsum, Vietnamese filler, Spanish, or hipster style. Words, sentences, paragraphs, or HTML.

Pretty-print or minify HTML with configurable indent, attribute wrapping, and self-closing handling. 100% local.

Pretty-print or minify CSS with configurable indent, selector separator, and brace style. 100% local.

Pretty-print or minify JavaScript with real AST. Beautify via js-beautify, minify via Terser. ES2024 syntax supported.

Convert text to and from hexadecimal bytes. UTF-8 safe — handles emoji, Vietnamese, CJK. Configurable separator and 0x prefix.

Convert text to and from 8-bit binary. UTF-8 safe. Configurable byte separator.

Convert text to \uXXXX or \u{XXXXX} escapes and back. Handles surrogate pairs for emoji. Output JSON-safe or ES2015 syntax.

Basal Metabolic Rate calculator using the Mifflin–St Jeor equation. Daily calorie burn at complete rest.

Daily calorie target calculator. BMR (Mifflin–St Jeor) × activity factor × goal adjustment. Returns TDEE and weight goal calories.

US Navy method body fat % from waist, neck, height (and hip for women). Quick estimate without calipers.

Compute pace from distance + time, or predict time from pace + distance. Min/km, min/mile, common race distances.

Calculate years, months, days, weeks between two dates. Handles leap years and short months correctly.

Original price + discount % → final price + amount saved. Optionally stack a sales tax.

Optimal bedtimes for waking refreshed. Based on 90-minute REM cycles + 14-minute fall-asleep average.

Count words, characters (with/without spaces), sentences, paragraphs. Live updates. Tweet-length tracker built in.

Estimate reading and speaking time from text. Adjustable WPM for different audiences.

One screen for all random picks: dice roll, coin flip, random number range, pick from a list.

Monthly payment + total interest from loan amount, rate, and term. User-input rate (no live rate fetch).

Monthly payment + interest for auto, personal, student loans. Amortization preview.

Expression-based scientific calculator. Trig, log, exp, factorial, constants. Keyboard-friendly.

Paste a list of numbers, get mean, median, mode, range, variance, standard deviation, quartiles.

Generate harmonized palettes: analogous, complementary, triadic, monochromatic. From a single seed color.

Convert between 30+ currencies. Rates from Frankfurter (ECB) cached 24h. Free, no API key needed.

Check color contrast against WCAG 2.2 AA/AAA — live preview, exact ratio, and an auto-suggested accessible color when your pair fails. 100% local.

IPv4 CIDR calculator — network, broadcast, usable host range, netmask, wildcard, binary view, class and private/public detection. 100% local.

Build cron expressions visually — presets for common schedules, per-field editing, plain-English description, and the next 5 run times. 100% local.

Structural JSON comparison — ignores key order and formatting, shows added/removed/changed values with exact paths. Smarter than a text diff. 100% local.

Hash passwords with bcrypt (choose cost rounds 4–15) and verify a password against an existing hash — everything runs in your browser, nothing is sent anywhere.

Generate RFC 6238 TOTP two-factor codes from a base32 secret — live countdown, QR code and otpauth:// URI for authenticator apps. Secrets never leave your browser.

Build linear, radial and conic gradients with as many colour stops as you need. Copy the CSS with a flat-colour fallback, or the Tailwind arbitrary value — and paste existing CSS back in to edit it.

Stack as many shadow layers as you need — offset, blur, spread, colour, inset — and see them on a light and a dark card at once. Copy the CSS or the Tailwind arbitrary value.

Drag the vertices of a polygon, or set up a circle, ellipse or inset, and copy the clip-path declaration. Twelve preset shapes, percentage or px output.

Open an .xlsx workbook, pick a sheet, and export it as CSV or JSON. Dates come out as dates, formulas as their results. Runs in your browser.

Turn a Word .docx into Markdown — headings, bold, lists, links and GFM tables. Clean HTML too. Runs in your browser.

Open the .heic photos an iPhone produces and save them as JPG or PNG. Decoded in your browser — the photos are never uploaded.

Cut the subject out of a photo and save a transparent PNG. The model runs in your browser — the image never leaves your device.

Encrypt or decrypt a piece of text with a password, using AES-256-GCM and PBKDF2. Runs in your browser — nothing is uploaded.

Generate an RSA (2048/3072/4096-bit) or Ed25519 key pair as PEM, right in your browser. Nothing is uploaded, and the private key never leaves the tab.

Compute an HMAC (SHA-1/256/384/512) with a text or hex key, hex or Base64 output, and verify a signature in constant time. Browser-only.

Find invisible characters and Latin-lookalike letters from other alphabets hiding in pasted text, then clean them. Runs in your browser.

Count OpenAI tokens (o200k_base or cl100k_base) plus characters and words for any pasted text. Runs entirely in your browser.

Drag two control points on a live grid and watch a block animate with that exact easing. CSS keyword and overshoot presets, copy as transition-timing-function or a custom property.

Upload a photo or enter a hex color and see it through protanopia, deuteranopia, tritanopia or achromatopsia. Side-by-side compare slider, matrices from the Brettel/Viénot-Mollon LMS model.

Pick a date and time, get all seven Discord <t:UNIX:STYLE> codes plus a live preview of how each renders — the same code shows different text to readers in different time zones.

Turn photos 90, 180 or 270 degrees, or flip them, one at a time or in a batch. Runs in your browser — nothing is uploaded.

Stamp text or a logo across a photo — position, opacity, size, angle, colour and tiling, with a live preview. Runs entirely in your browser.

Turn an image into a base64 data URI ready to paste into HTML, CSS or Markdown — and back again. Runs entirely in your browser.

Lock a PDF with a password, or remove one you already know. Runs entirely in your browser — nothing is uploaded.

Validate JSON data against a JSON Schema (draft-07 or 2020-12) and see exactly which field failed. Or go the other way: infer a schema from one sample. Browser-only.

Decode a Protocol Buffers payload to JSON — paste a .proto for real field names, or decode blind by wire format alone when you only have the bytes. Browser-only.

Decode a MessagePack payload to JSON, or encode JSON to MessagePack, with a byte-count comparison. Accepts hex, Base64, or an uploaded .msgpack file. Browser-only.

Sign a JWT with HS256/384/512 or RS256/ES256, and verify a token against a secret or public key — signature, expiry and alg:none checked separately. Runs in your browser.

Inspect a PEM or DER (.cer/.crt/.der) X.509 certificate — subject, issuer, validity, SAN, key usage, fingerprints. Certificate chains parsed in order. Runs in your browser.

Run jq filters against JSON right in the tab, with clickable examples for select/map/group_by/to_entries. Browser-only.

A real SQLite database in the tab. Type CREATE/INSERT, upload a .sqlite/.db file, or import a CSV as a table, then query it. Browser-only.

Shrink a scanned or image-heavy PDF by recompressing its embedded JPEG and raw (FlateDecode) images with MozJPEG or lossless PNG, optionally capping their resolution. Runs in your browser — the file is never uploaded.

Convert a TTF/OTF to WOFF (or back), and subset a font down to only the characters you need. Runs in your browser — nothing is uploaded.

Cut a clip out of an mp3, wav, ogg or m4a on a waveform, listen back, and download the result as a .wav. Runs in your browser — nothing is uploaded.

Rotate, zoom and inspect a .stl or .obj 3D model — triangle count, bounding box, estimated volume, wireframe toggle, PNG snapshot. Runs in your browser, nothing is uploaded.

Validate Ethereum (EIP-55), Bitcoin (legacy/segwit/bech32), and Solana addresses. Browser-only, no blockchain queries.

Convert between Ethereum units (wei, gwei, ether, etc.). BigInt math, no precision loss.

Generate QR codes for text, URLs, vCard, Wi-Fi, or email — PNG and SVG download, error correction levels, color customization. 100% local.

Convert images between PNG, JPEG, and WebP in your browser. Quality slider for lossy formats. AVIF input supported (decode). Max 10 MB. 100% local.

Add or remove sales tax from a price. Configurable rate. No tax tables — bring your own rate.

Project retirement balance from current savings, monthly contribution, return rate, and retirement age.

What do I need on the final? Given current grade + final weight + target grade, calculate the required score.

Estimated due date from last menstrual period (Naegele's rule, 40 weeks). For information only — not medical advice.

Sum daily work hours from clock-in/clock-out times, subtract unpaid breaks. Weekly total + pay.

Solve a triangle: three sides → angles + area (Heron). Pythagorean check for right triangles.

Convert shoe sizes across US, EU, UK, and JP (cm). Men, women, kids. Approximate — brands vary.

Flesch Reading Ease + Flesch-Kincaid Grade Level + Gunning Fog. English text only.

Convert nightly tips + base wage + hours worked into effective hourly rate. For service workers.

25-minute focus blocks with 5-minute short breaks and 15-minute long breaks. Audio cue via Web Audio oscillator.

Convert Unix file permissions between checkboxes, octal (755) and symbolic (rwxr-xr-x) — setuid/setgid/sticky included, chmod command ready to copy. 100% local.

Searchable reference for every common HTTP status code (what it really means) plus file-extension → MIME type lookup. Instant filter, works offline.

Sketch diagrams and wireframes in the browser. Saved in this browser only — no account, no sync, nothing uploaded.

Generate, validate and convert BIP-39 mnemonic phrases (12–24 words) — entropy, checksum and seed derivation, English wordlist. Runs in your browser, for learning and testing only.