UUID Generator
Generate cryptographically random UUID v4 or time-ordered UUID v7, in bulk.
Free tools for developers and SEOs
Every DevSEOCraft tool in one place. All of them run in your browser, need no signup, and never send what you paste to a server.
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Developer tools
119Base64 Encoder & Decoder
Encode and decode Base64 with correct UTF-8 handling, including the URL-safe alphabet.
ULID Generator
Generate ULIDs — sortable by creation time like UUID v7, but Crockford Base32 instead of hex.
URL Encoder & Decoder
Percent-encode or decode a URL, a query parameter, or a form-urlencoded value — three different modes, not one.
Password Generator
Generate a random password with Web Crypto, and see exactly how strong it actually is.
Password Strength Tester
Test any password against zxcvbn — real strength score, crack time and feedback.
Morse Code Converter
Convert text to Morse code and back with audio beeps and a light flash.
Binary Text Converter
Convert text to binary and back with full UTF-8, ASCII and emoji support.
Passphrase Generator
Generate a memorable, cryptographically random passphrase from a fixed 256-word list.
Regex Tester
Test a regular expression against real text and see every match, group and named capture highlighted.
Fancy Text Generator
Type once, get a dozen stylized Unicode text variants — bold, italic, bubble and more — to copy and paste anywhere.
Upside Down Text Generator
Flip any text ʇxǝʇ uʍop ǝpᴉsdn — copy and paste it anywhere plain text works.
Bubble Text Generator
Turn text into Ⓒⓘⓡⓒⓛⓔⓓ letters — copy and paste anywhere plain text works.
Strikethrough Text Generator
Turn text into s̶t̶r̶i̶k̶e̶t̶h̶r̶o̶u̶g̶h̶ — works in places that have no formatting toolbar at all.
Small Text Generator
Turn text into ꜱᴍᴀʟʟ ᴄᴀᴘꜱ — copy and paste anywhere plain text works.
Zalgo Text Generator
T̸̢̛h̷̗͝ḙ̶̅ ̴̱̌c̶͇̈h̶̗̽a̴͙͐o̸̢͒t̶̳̽i̷̘͐c̷̮̈, "̷g̶l̸i̶t̷c̸h̷e̶d̸-̶o̸u̸t̷"̶ ̸t̴e̷x̴t̶ ̵e̸f̸f̶e̴c̸t̸.
Discord Font Generator
Stylized text for a Discord name, nickname or message — pick a style that actually renders there.
Instagram Fonts Generator
Stylized text for an Instagram bio, caption or name field — a dozen styles from one input.
Word & Character Counter
Count words, characters, sentences and paragraphs, with an estimated reading time.
Text to Speech
Paste any amount of text and have your browser read it aloud — no length limit, no account.
Emoji Picker
Searchable online emoji keyboard — browse categories, build a string in a tray, copy and paste, with recent picks stored locally.
NATO Phonetic Alphabet Converter
Spell text as Alfa Bravo Charlie — or decode phonetic words back to letters.
JWT Decoder
Decode the header and payload of a JWT without the token ever leaving your browser.
JSON Formatter & Validator
Pretty-print, minify or validate JSON, with the exact line and column of any syntax error.
JSON Path Finder
Paste JSON, explore its tree and build JSONPath queries by clicking nodes — live results.
Unix Timestamp Converter
Convert epoch timestamps to readable dates and back, with automatic unit detection.
Color Converter
Convert between hex, RGB, HSL and HSB, with a live WCAG contrast ratio check.
Timezone Converter
See what a specific time in one timezone looks like in twenty others, at a glance.
Number Base Converter
Convert a number between binary, octal, decimal and hexadecimal — any base from 2 to 36, actually.
Unit Converter
Convert length, weight or temperature between the units people actually use — metric and imperial.
Roman Numeral Converter
Convert between numbers and Roman numerals, both directions, live as you type.
CSS Gradient Generator
Build a linear or radial gradient with as many color stops as you need, with a live preview.
CSS Box-Shadow Generator
Stack multiple shadow layers, inner or outer, with a live preview and the exact CSS to copy.
CSS Grid Generator
Live CSS Grid preview with gaps, track templates, and named spans to copy.
CSS Flexbox Generator
Live flexbox playground: direction, wrap, justify, align, gap, and child flex.
CSS Border-Radius Generator
Build a rounded corner, a circle, or an organic blob shape — full 8-value control, not just one radius.
CSS Clamp Calculator
Fluid font-size or spacing from four numbers — a min, a max, and the viewport range between them.
CSS Specificity Calculator
Paste one or more selectors and see the exact (IDs, classes, elements) triple that decides which rule wins.
CSS Unit Converter
px, rem, em, pt and % — enter one, get all the others instantly, with a configurable base font size.
CSS Minifier
Strip comments and whitespace — without breaking calc(), which naive minifiers quietly corrupt.
HTML Minifier
Compress HTML — strip whitespace, remove comments and minify inline CSS and JS.
XML Formatter
Format, minify or validate XML, with real mismatched-tag and unclosed-tag errors — not just "invalid".
YAML Formatter
Normalize inconsistent YAML indentation, or check it parses cleanly, with line numbers on syntax errors.
SQL Formatter
Format SQL with real clause-aware indentation across 6 dialects — a parser under the hood, not keyword regex.
XML to JSON Converter
Convert XML to JSON with a documented, predictable attribute/text mapping — repeated tags become arrays automatically.
JSON to XML Converter
Convert JSON to pretty XML with @attr / #text conventions and array siblings.
JSON to TypeScript Converter
Paste JSON, get TypeScript interfaces or types — nested, optional, export-ready.
HTML Table Generator
Build an HTML table with an editable grid, live preview, and optional CSS.
CSV Viewer / Editor
Paste or upload CSV, edit cells in a table, and re-export locally.
Excel to JSON Converter
Convert .xlsx / .xls spreadsheets to pretty JSON in your browser — free and local.
Mock Data Generator
Generate fake users, products, or custom rows as JSON or CSV.
SVG to PNG Converter
Paste or drop an SVG and get a downloadable PNG, sized from the SVG's own intrinsic dimensions.
UUID v5 Generator
Deterministic UUIDs from a namespace and a name — the same input always produces the same UUID.
curl Command Generator
Build a curl command from method, URL, headers and body — with shell-safe quoting handled for you.
htpasswd Generator
Generate an Apache htpasswd line — bcrypt (current default) or the legacy {SHA} format.
.gitignore Generator
Combine .gitignore templates for any mix of languages, tools and OSes, deduplicated automatically.
Merge PDF
Combine multiple PDFs into one, in whatever order you drop them — reorder before downloading.
Split PDF
Extract page ranges into separate PDFs — one download per range you specify.
Remove Pages from PDF
Delete specific pages from a PDF and download the rest, without touching the ones you keep.
Rotate PDF
Rotate all pages or just the ones you name, 90° at a time — repeated clicks add up correctly.
Watermark PDF
Stamp text diagonally across every page — DRAFT, CONFIDENTIAL, or anything else, with adjustable size, color and opacity.
PDF to JPG Converter
Render every page of a PDF as a downloadable JPG — rasterized by the same engine that draws PDFs in Firefox.
PDF to Text Converter
Extract the real, selectable text from a PDF — with an honest warning when a page is actually a scanned image.
BMI Calculator
Metric or imperial, with the standard WHO categories — and an honest note on what BMI does not measure.
Age Calculator
Exact age in years, months and days as of any date — calendar-aware, not a rough days-divided-by-365 estimate.
Percentage Calculator
The three percentage questions people actually ask — "X% of Y", "X is what % of Y", and "% change from X to Y" — in one tool.
Fraction Calculator
Add, subtract, multiply, divide, simplify, and convert fractions locally.
Loan Calculator
Monthly payment, total paid and total interest from principal, rate and term — the standard amortization formula.
GPA Calculator
Add each course's grade and credit hours and get the properly credit-weighted GPA — not a plain average of grades.
Grade Calculator
Weighted grade average from scores & weights, or what you need on the final.
Discount Calculator
Stack multiple discounts correctly — "20% off, plus an extra 10%" is not 30% off, and this shows exactly why.
Tip Calculator
Bill, tip %, tax, and split — tip, total, and per-person share instantly.
Salary Converter
Convert annual ↔ monthly ↔ biweekly ↔ weekly ↔ hourly — gross rates, instantly.
Amortization Schedule Calculator
Loan payment table: principal, interest, balance, optional extras.
Inflation Calculator
What is $X in year A worth in year B? US CPI purchasing power, instantly.
Standard Deviation Calculator
Paste numbers — sample & population stdev, mean, variance, with optional steps.
Compound Interest Calculator
Future value with optional recurring contributions — and a clear breakdown of how much is your money versus how much is interest.
Date Difference Calculator
Exact time between any two dates in years, months and days — calendar-aware, plus the total day count.
Business Days Calculator
Count working days between two dates, with your own list of holidays to exclude — no assumed country calendar.
Time Duration Calculator
Hours between times, overnight shifts with breaks, or add/subtract durations.
Random Number Generator
Cryptographically random integers in any range — the same random source used for encryption keys, not Math.random.
Dice Roller
Roll any number of dice with any number of sides — cryptographically random, not a predictable Math.random roll.
Random Name Generator
Generate random regular or fantasy names, in bulk, for characters, test data or brainstorming.
Barcode Generator
CODE128, EAN-13, UPC and CODE39 — with the format-specific validation that most barcode generators skip.
QR Code Scanner
Drop or upload an image with a QR code and read what it says — decoded locally, no camera required.
Case Converter
Convert text between camelCase, PascalCase, snake_case, kebab-case and more, all at once.
Cron Expression Parser & Generator
Build a cron schedule from a simple form, or paste one and get it explained in plain English.
DNS Lookup
Free DNS lookup online — query A, MX, TXT, AAAA and more via Cloudflare DoH.
Whois Lookup
Free whois lookup online via RDAP — domain whois check and IP lookup.
SSL Certificate Checker
Free SSL certificate checker online — CT issuer, dates & serial.
HTTP Headers Viewer
Check HTTP headers online — response headers and security headers at a glance.
SHA Hash Generator
Compute SHA-1, SHA-256, SHA-384 and SHA-512 digests of any text, in your browser.
AES Encryption / Decryption
AES-256-GCM encrypt & decrypt in your browser — plaintext never uploaded.
IP Subnet Calculator
Enter an IP and CIDR prefix and get the network, broadcast, mask and usable host range.
User-Agent Parser
Paste a User-Agent string and see the browser, engine, OS and device type it actually describes.
Image to Base64 Converter
Convert an image to a Base64 data URI you can paste straight into CSS, HTML or JSON.
Image Resizer
Resize an image to exact pixel dimensions, with aspect ratio locked or unlocked.
Image Compressor
Shrink an image file size with a live quality slider, comparing original and compressed size.
PNG to JPG Converter
Convert PNG to JPG with a chosen background color filling transparent areas.
WebP Converter
Convert PNG/JPG/GIF to WebP or WebP to PNG/JPG — free in your browser.
HEIC to JPG Converter
Convert iPhone HEIC/HEIF to JPG in your browser — free, local, batch-ready.
SVG Optimizer
Minify SVG in the browser — strip comments, collapse whitespace, shrink colors.
Image to Text OCR
Free image to text OCR online — extract text from JPG, PNG, or WebP locally.
EXIF Data Viewer
View EXIF/GPS metadata in your browser — strip tags before you share.
Color Palette from Image
Extract the dominant colors from an image, ranked by how often they appear.
Placeholder Image Generator
Generate a placeholder image at any size, with custom colors and text, no external URL needed.
Email Validator
Check one email or a whole pasted list, with a specific reason for every one that fails.
JSON to YAML Converter
Convert JSON to YAML and back, with real duplicate-key detection instead of a silent overwrite.
CSV to JSON Converter
Convert CSV to a JSON array of objects and back, with a real parser that handles quoted commas correctly.
Markdown Table Generator
Paste data copied from a spreadsheet and get a properly padded, pipe-aligned Markdown table.
Markdown to HTML Converter
Paste Markdown, get clean HTML with a live preview — GFM tables and fenced code included.
HTML Entity Encoder & Decoder
Escape text for safe use inside HTML, or decode entities back to readable characters.
Remove Duplicate Lines
Dedupe, sort and clean up a list — case-sensitive or not, blank lines and whitespace handled too.
Email Extractor
Paste any block of text and pull out every email address it contains, deduplicated.
ASCII Art Text Generator
Turn text into a block-letter ASCII banner, ready to paste into a code comment or a terminal.
Text Diff Checker
Compare two blocks of text line by line and see exactly what changed.
.env Validator
Catch quoting, duplicate and syntax bugs in a .env file before they break your deploy.
ROT13 / Caesar Cipher
Shift text by any amount — ROT13 is just shift 13, its own inverse.
HTTP Status Code Lookup
Search HTTP status codes by number or keyword, with the ones that actually confuse people explained.
SEO tools
40Morse Code Converter
Convert text to Morse code and back with audio beeps and a light flash.
Binary Text Converter
Convert text to binary and back with full UTF-8, ASCII and emoji support.
Word & Character Counter
Count words, characters, sentences and paragraphs, with an estimated reading time.
Text to Speech
Paste any amount of text and have your browser read it aloud — no length limit, no account.
Keyword Density Checker
Paste your content and see which words and phrases actually repeat, and how often.
Readability Score Checker
Paste your content and get its Flesch Reading Ease score and grade level, not just a word count.
X (Twitter) Character Counter
Count your post the way X actually counts it — links always cost 23 characters, CJK text costs double.
Social Media Character Counter
Paste once and check Instagram, LinkedIn, TikTok, Facebook, Threads, YouTube, X and Bluesky limits side by side.
Emoji Picker
Searchable online emoji keyboard — browse categories, build a string in a tray, copy and paste, with recent picks stored locally.
Meta Tag Generator
Generate a complete <head> block: title, description, canonical, Open Graph and Twitter Card.
Meta Description Generator
Write SEO meta descriptions with live length scoring and rewrite ideas.
Blog Title Generator
Generate 10–15 SEO blog title ideas from a keyword, with tone presets and live character counts.
Text Summarizer
Summarize long text online free with an extractive, in-browser summarizer — no generative AI API.
Article Rewriter
Rewrite drafts with local synonyms, voice toggles and a strength slider.
QR Code Generator
Turn a URL or any text into a downloadable QR code, with a choice of error correction level.
UTM Builder
Build campaign URLs that GA4 actually attributes, with the mistakes flagged as you type.
Redirect Checker
Trace 301/302/meta redirect chains for any URL — free, hop-by-hop.
Open Graph Preview Checker
Fetch a URL and preview how Open Graph / Twitter Card tags look as Facebook- and X-style share cards.
Event Schema Generator
Generate valid Event JSON-LD for a physical or online event, with the correct attendance-mode value set automatically.
Organization Schema Generator
Generate valid Organization JSON-LD — the site-identity markup Google reads for Knowledge Panels.
Course Schema Generator
Generate valid Course JSON-LD — with the description Google actually requires here, unlike most other schema types.
Robots.txt Generator
Build a robots.txt file with rule groups, a sitemap line, and a check for the mistake that deindexes a site.
XML Sitemap Generator
Paste a list of URLs and get a valid sitemap.xml, ready to upload — no crawler required.
DNS Lookup
Free DNS lookup online — query A, MX, TXT, AAAA and more via Cloudflare DoH.
Whois Lookup
Free whois lookup online via RDAP — domain whois check and IP lookup.
SSL Certificate Checker
Free SSL certificate checker online — CT issuer, dates & serial.
HTTP Headers Viewer
Check HTTP headers online — response headers and security headers at a glance.
Favicon Generator
Upload one image and get every favicon size a real site needs, plus the HTML tags to reference them.
SERP Snippet Preview
See how your title and meta description will be truncated in Google, measured in pixels.
URL Slug Generator
Turn any headline into a clean, ASCII-safe URL slug, accents and symbols included.
Lorem Ipsum Generator
Generate placeholder text by words, sentences or paragraphs, with the classic opener if you want it.
FAQ Schema Generator
Turn a list of questions and answers into valid FAQPage JSON-LD, checked against Google's rules.
Article Schema Generator
Generate valid Article, NewsArticle or BlogPosting JSON-LD, with the fields Google actually checks.
Product Schema Generator
Generate valid Product JSON-LD with offer, price and rating — checked against what Google actually requires.
Review Schema Generator
Generate valid Review JSON-LD — with a direct reminder that self-reviews are exactly what Google excludes.
HowTo Schema Generator
Generate valid HowTo JSON-LD from a title and a list of steps — with duration in the format Google actually expects.
LocalBusiness Schema Generator
Generate valid LocalBusiness JSON-LD with address, hours and contact info, checked against Google's required fields.
Breadcrumb Schema Generator
Generate valid BreadcrumbList JSON-LD, with the current page correctly left URL-less.
Schema Markup Validator
Paste JSON-LD and get it checked against the real required fields — not just "is this valid JSON."
Hreflang Generator
Generate a valid hreflang tag set from a list of language and region URLs.