kodilo
238 open-source tools for developers. No sign-up, no account, nothing leaves your browser.
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EmailPreview and test outgoing HTML email
JSONFormat, validate, diff, convert
- JSON Formatter & ValidatorFormat, validate and minify JSON data.
- JSON to YAMLConvert JSON to YAML.
- JSON to CSVConvert JSON arrays to CSV.
- JSON DiffCompare two JSON documents and highlight what changed.
- JSON ViewerExplore a JSON document as a collapsible tree.
- JSON to TypeScriptGenerate TypeScript interfaces or types from a JSON sample.
- JSON Schema ValidatorValidate JSON against a JSON Schema, or generate a schema from data.
- JSONPath TesterRun JSONPath expressions against a JSON document and see every match with its exact path, live as you type.
- JSON to ZodGenerate a Zod schema from a JSON sample, with nested objects, arrays and optional keys.
- JSON to GoGenerate Go structs with json tags from a JSON sample.
- JSON to OpenAPI SchemaInfer an OpenAPI 3.1 component or JSON Schema from JSON samples, with formats.
HTML / CSSBeautify, minify, generate
- HTML FormatterBeautify and format HTML code.
- CSS Formatter & MinifierFormat and minify CSS stylesheets.
- SVG to JSX, TSX & VueTurn an SVG into a React or Vue component with size and color props.
- Box Shadow GeneratorGenerate CSS box-shadow values with a live preview.
- Gradient GeneratorGenerate CSS gradients with a live preview.
- CSS Grid GeneratorBuild a CSS grid layout visually and copy the code.
- Flexbox GeneratorBuild a CSS flexbox layout visually and copy the code.
- XML FormatterPretty-print or minify XML and catch well-formedness errors.
- Code MinifierMinify JavaScript, CSS or HTML and see how many bytes you saved.
- CSS clip-path EditorDrag handles to shape a polygon, circle, ellipse or inset clip-path and copy the CSS.
- CSS Keyframes GeneratorBuild @keyframes animations step by step with timing, iteration and a live preview.
- Media Query TesterSee which media queries match at any width, orientation, color scheme or pointer, with a live resizable preview.
- Fluid Clamp GeneratorMin and max sizes between two viewports turned into CSS clamp() values.
- Text Shadow GeneratorLayered text-shadow for soft, neon, retro or outline type.
- CSS Filter Generatorfilter and backdrop-filter functions tuned on a sample image.
- Border Radius GeneratorAll 8 border-radius values with drag handles for organic shapes.
- Scrollbar Stylerscrollbar-color and scrollbar-width with a ::-webkit-scrollbar fallback.
- CSS Triangle GeneratorTriangles in 8 directions with borders or clip-path.
- CSS Specificity Calculator(a, b, c) specificity for a list of selectors, sorted and explained.
- CSS Selector TesterPaste HTML, type a selector, see every match highlighted.
- Tailwind CSS ConverterCommon Tailwind utilities to plain CSS and back.
MarkdownWrite, preview, convert
- Markdown to HTMLConvert Markdown to HTML.
- Markdown PreviewerWrite Markdown and preview the rendered result live.
- HTML to MarkdownConvert HTML or pasted rich text to clean Markdown.
- Mermaid Live EditorWrite Mermaid diagrams and see them rendered live, then copy or download the SVG. Flowcharts, sequences, classes, Gantt and ER.
- Markdown Table GeneratorBuild a Markdown table in an editable grid or import CSV or TSV, with per-column alignment, padded columns and escaped pipes.
- README Badge GeneratorBuild shields.io badges for your README, with GitHub and GitLab presets, a live preview and Markdown, HTML or reStructuredText output.
- Issue & PR Template GeneratorCreate GitHub issue forms and pull request templates, and GitLab issue and merge request templates with quick actions, ready to drop in your repo.
SEOMeta tags for link previews
- Meta Tag GeneratorGenerate HTML meta tags.
- Open Graph GeneratorGenerate Open Graph tags for link previews.
- robots.txt GeneratorWrite robots.txt rules per crawler, block AI bots and test a path.
- Sitemap GeneratorTurn a list of pages into a valid sitemap.xml.
- HTML Meta AuditAudit a page's title, description, social cards, icons, headings, alt text and JSON-LD with a score.
TextCase, diff, count, encode
- Regex TesterTest regular expressions against sample text.
- Diff CheckerCompare two texts side by side.
- Case ConverterConvert text between case styles (camel, snake, kebab...).
- Word CounterCount words, characters and lines.
- SlugifyTurn text into a URL-friendly slug.
- Lorem Ipsum GeneratorGenerate placeholder text.
- Text to BinaryConvert text to and from binary.
- Text to NATO AlphabetSpell out text using the NATO phonetic alphabet.
- Text StatisticsReading time, sentence count and other text metrics.
- Numeronym GeneratorGenerate numeronyms like i18n or a11y from a word.
- Unicode InspectorInspect every character with its code point, bytes and escapes, and find invisible ones.
- Line ToolsSort, deduplicate, trim, filter, reverse, shuffle or number lines of text, with input and output line counts.
- ASCII Table GeneratorDraw CSV or TSV data as ASCII or Unicode box tables in several styles.
- ASCII Art GeneratorTurn text into ASCII banners with classic FIGlet fonts.
Encoding & SecurityHash, sign, encrypt, decode
- Base64 Encoder & DecoderEncode and decode Base64 strings.
- JWT DecoderDecode and inspect JWT tokens.
- URL Encoder & DecoderEncode and decode URL strings.
- HTML EntitiesEncode and decode HTML entities.
- Hash TextGenerate MD5, SHA-1, SHA-256 and other hashes.
- HMAC GeneratorGenerate an HMAC signature for a message and key.
- BcryptHash and verify passwords with bcrypt.
- Basic Auth GeneratorGenerate an HTTP Basic Authentication header.
- Token GeneratorGenerate random tokens with a custom charset and length.
- RSA Key Pair GeneratorGenerate an RSA public/private key pair.
- Text EncryptionEncrypt and decrypt text with AES and a passphrase.
- BIP39 GeneratorGenerate a BIP39 mnemonic seed phrase.
- XOR CipherEncrypt or decrypt text/bytes with a repeating XOR key.
- Checksum CalculatorCompute a CRC32 or other checksum for text or a file.
- String EscaperEscape or unescape strings for JSON, JS, SQL, shell, regex, CSV and HTML.
- TOTP / 2FA GeneratorGenerate and check time-based one-time passwords with a QR code.
- JWT GeneratorSign JSON Web Tokens with HS256, RS256 or ES256 and verify them.
- CSP GeneratorBuild a Content-Security-Policy with warnings for risky values.
- Base32, Base58 & Hex EncoderEncode and decode UTF-8 text as Base32 (RFC 4648), Base58 (Bitcoin alphabet) or hex, and list each character's code point and bytes.
- CSR GeneratorCreate a certificate signing request and its private key for RSA or ECDSA, with subject fields and DNS alternative names.
- RBAC Matrix BuilderBuild a roles × resources × actions grid with scopes and inheritance, then export JSON, YAML, a Spatie seeder, CASL or SQL.
- Permission TesterCheck whether a role may perform an action on a record, with the deciding rule and the inheritance chain.
- Policy DiffCompare two role matrices: granted, revoked, widened and narrowed permissions per role, with risky escalations flagged.
- Password Strength CheckerEstimate entropy and crack time per attack scenario, spot weak patterns and get advice. Never stored.
- SAML DecoderDecode SAMLRequest and SAMLResponse messages: issuer, NameID, validity, audience, attributes and signature.
- OAuth & OIDC HelperBuild an OAuth 2.0 or OIDC authorization URL with PKCE, state and nonce, and decode callbacks and tokens.
- SSH Key GeneratorGenerate Ed25519 or RSA SSH key pairs in OpenSSH format with a comment and SHA256 fingerprint.
- Webhook Signature VerifierVerify GitHub, Stripe, Slack, Shopify and HMAC webhook signatures.
GeneratorsIDs, passwords, QR, cron
- UUID GeneratorGenerate random UUIDs.
- ULID GeneratorGenerate ULIDs (sortable unique identifiers).
- Password GeneratorGenerate secure random passwords.
- QR Code GeneratorGenerate QR codes from text or URLs.
- WiFi QR Code GeneratorGenerate a QR code that connects to a WiFi network.
- Crontab GeneratorBuild and explain a cron expression.
- Fake Data GeneratorGenerate realistic fake records as JSON, CSV or SQL INSERT statements, with a seed for reproducible output.
- License GeneratorPick an open source license, enter the year and copyright holder, and get a ready LICENSE file with what it allows, requires and limits.
ConvertersDates, colors, bases, units
- Date/Time ConverterConvert between timestamps, ISO dates and time zones.
- Color ConverterConvert colors between HEX, RGB, HSL and more.
- Integer Base ConverterConvert numbers between binary, octal, decimal and hex.
- Roman Numeral ConverterConvert numbers to and from Roman numerals.
- Temperature ConverterConvert between Celsius, Fahrenheit and Kelvin.
- TOML Formatter & ConverterValidate and format TOML, convert it to and from JSON.
- CSV to JSONTurn CSV into JSON with automatic delimiter detection, header rows and typed numbers, booleans and nulls.
- Time Zone ConverterConvert a date and time from one time zone to many others, with UTC offsets, day changes and daylight saving handled automatically.
- XML ⇄ JSON ConverterConvert XML to JSON and JSON back to XML, with attributes and repeated elements preserved.
- SQL to TypeScript & PrismaTurn CREATE TABLE statements into TypeScript interfaces and Prisma models.
- CSV CleanerTrim cells, drop duplicate and empty rows, remove empty columns and sort CSV.
- SQL ↔ CSV ConverterTurn CSV into INSERT statements for four SQL dialects, or INSERT VALUES back into CSV.
- Protobuf & MessagePack DecoderDecode hex or base64 as MessagePack or raw protobuf, optionally with a .proto schema, and encode JSON to MessagePack.
NetworkIPs, MACs, user agents, status codes
- IPv4 Subnet CalculatorCalculate subnet ranges, masks and host counts.
- IPv4 Range ExpanderExpand an IPv4 range or CIDR into individual addresses.
- IPv6 ULA GeneratorGenerate a unique local IPv6 address prefix.
- MAC Address GeneratorGenerate random MAC addresses.
- MAC Address LookupLook up the vendor for a MAC address.
- User Agent ParserParse a User-Agent string into browser, engine and OS.
- HTTP Status CodesLook up the meaning of an HTTP status code.
- Phone Parser & FormatterParse and format international phone numbers.
- URL ParserSplit a URL into its parts and edit query parameters.
- HTTP Headers & Cookie ParserPaste raw request or response headers to see each one explained, with Cache-Control, CSP and Set-Cookie decoded and common mistakes flagged.
- CIDR Aggregator & SplitterMerge IPv4 addresses, ranges and CIDRs into the smallest CIDR list, subtract exclusions, or split a network into equal subnets.
- HAR ViewerOpen a .har capture to see a waterfall, sortable requests, headers, cookies and bodies, and export a sanitized copy.
ValidatorsEmails, cards, IBANs
ImagesResize, compress, convert
- Image ResizerResize images entirely in the browser.
- Image CompressorCompress images without uploading them anywhere.
- PNG to JPG ConverterConvert PNG images to JPG.
- Image to Base64Convert an image to a Base64 data URI.
- SVG OptimizerShrink SVG files with SVGO and compare the result.
- WebP & AVIF ConverterConvert images to WebP or AVIF, or back to JPG and PNG.
- EXIF Viewer & RemoverSee photo metadata such as camera and GPS, and download a clean copy.
- QR Code ReaderRead a QR code from an image, a pasted screenshot or the camera.
- Code ScreenshotTurn a code snippet into a clean image with syntax highlighting, window chrome and a gradient background, exported as a 2x PNG.
- Placeholder Image GeneratorMake placeholder images of any size with your colors and label, as PNG, JPG, WebP or SVG, plus a data URI and an SVG snippet.
- srcset & sizes GeneratorResponsive img srcset and sizes or picture with AVIF and WebP, and which file the browser picks.
PDFMerge, split, compress, convert
Dev UtilitiesSQL, cron, chmod, MIME
- Text CompressorCompress or decompress text with gzip, deflate or deflate-raw, and see the size saved. Output as Base64 or hex.
- SQL PrettifyFormat SQL queries.
- Math EvaluatorEvaluate a math expression on the fly.
- Docker Run to Compose ConverterConvert a docker run command to a docker-compose.yml.
- MIME TypesLook up the MIME type for a file extension.
- Chmod CalculatorCompute and explain Unix file permission values.
- Regex CheatsheetQuick reference for common regular expression syntax.
- REST API TesterSend a request and inspect the response, no app install needed.
- Docker CheatsheetQuick reference for common Docker commands.
- Git CheatsheetQuick reference for common Git commands.
- NPM CheatsheetQuick reference for common npm/pnpm/yarn commands.
- GraphQL FormatterFormat or minify GraphQL queries and schemas.
- Keyboard Event InfoPress a key to see event.key, event.code, keyCode and modifiers.
- JavaScript Formatter & MinifierBeautify JavaScript or TypeScript with Prettier, or minify it with Terser and see how many bytes you save.
- CODEOWNERS GeneratorMap paths to owners for GitHub or GitLab, with sections and approvals, owner validation and shadowed pattern warnings.
- Conventional Commit BuilderWrite a Conventional Commits message with live checks and a ready git commit command, or paste one to validate it and see the semver bump.
- Git Undo GuidePick what went wrong and get the exact Git commands to fix it, with a warning on the ones that rewrite history.
- Regex ExplainerBreak a regular expression into tokens and read what each one does in plain English.
- Glob TesterTest glob patterns against a list of paths and see which ones match, live.
- PHP FormatterBeautify PHP with Prettier and its PHP plugin, PER brace style and quote options.
- Python FormatterNormalize Python indentation, PEP 8 spacing, quotes and blank lines.
- YAML FormatterReformat YAML with consistent indentation and quotes, optionally sorting keys.
- Git Log Graph ExplainerPaste git log --graph output and get a clean commit graph with branches, merges and tags explained.
- Git Rebase vs Merge VisualizerBefore and after diagrams of merge, rebase, squash and cherry-pick on the same history, with the commands.
- .gitattributes GeneratorBuild a .gitattributes file with line endings, binary files, Git LFS, linguist overrides and diff drivers.
- SQL EXPLAIN ExplainerRead Postgres and MySQL EXPLAIN plans as a tree with cost bars and plain-English advice.
- SQL to ER DiagramDraw an ER diagram from CREATE TABLE statements, export Mermaid or SVG.
- OpenAPI Viewer & ValidatorValidate an OpenAPI 3.x or Swagger 2.0 spec and browse its endpoints by tag.
DevOps & SysadminServers, containers, uptime, config
- Uptime / SLA CalculatorTurn 99.9% into allowed downtime per day, month and year, and back.
- Byte Size ConverterB, KB, KiB, MB, MiB, GB, GiB, TB, TiB: decimal and binary units side by side.
- Transfer Time CalculatorHow long a file takes to move over a given bandwidth, and the bandwidth a deadline needs.
- Kubernetes Resource UnitsCPU millicores and memory quantities (Mi, Gi, M, G) converted and explained.
- Kubernetes Manifest GeneratorDeployment, Service and Ingress YAML from a short form.
- .env ToolValidate, diff and convert .env files to JSON, docker -e flags or a Kubernetes Secret.
- YAML Validator & FormatterValidate YAML with line-precise errors, format it, convert it to JSON.
- Nginx Config GeneratorReverse proxy, static site, SPA fallback, HTTPS redirect and gzip in a few clicks.
- systemd Unit GeneratorService and timer units with restart policy, user, environment and hardening options.
- SSH Config GeneratorHost blocks for ~/.ssh/config with jump hosts, identity files and port forwarding.
- htpasswd Generatorbcrypt or SHA entries for Nginx and Apache basic auth.
- DNS Record BuilderSPF, DMARC, CAA and MX records built and explained, ready to paste.
- Security Headers BuilderContent-Security-Policy, HSTS, Permissions-Policy and friends, for Nginx, Apache or a meta tag.
- X.509 Certificate DecoderPaste a PEM certificate: subject, issuer, SANs, validity, fingerprints.
- SemVer CalculatorCompare versions and test ranges like ^1.2.0, ~2.3 or >=1 <2.
- .gitignore GeneratorCombine templates for languages, frameworks, editors and operating systems.
- JSON Log ViewerPaste structured logs, filter by level and field, read them as a table.
- curl ConverterTurn a curl command into fetch, axios, Python requests or HTTPie.
- Well-Known PortsSearchable reference of common TCP and UDP ports and the services behind them.
- Linux Signals & Exit CodesWhat SIGTERM, SIGKILL or exit code 137 actually mean.
- Redirect GeneratorWrite redirects once and get Nginx, Apache, Netlify, Vercel and Caddy rules.
- GitHub Actions Workflow GeneratorGenerate a CI workflow for Node, Python, Go, Docker or GitHub Pages with a version matrix, caching, least-privilege permissions and concurrency control.
- Dockerfile Generator & LinterGenerate a multi-stage Dockerfile with a non-root user, health check and .dockerignore, or lint an existing Dockerfile line by line.
- Docker Compose ValidatorValidate a compose file for YAML errors and semantic mistakes like bad ports, unknown services, undefined networks and volumes.
- Kubernetes Secret EncoderTurn key/value pairs or a .env file into a Secret manifest with UTF-8 safe base64, or decode an existing Secret.
- Caddyfile GeneratorBuild a Caddyfile with a reverse proxy or static site, www redirect, basic auth, security headers, compression and logging.
- Firewall Rule GeneratorDescribe your firewall rules once and get them as ufw commands, an iptables-save file or a complete nftables ruleset.
- Logrotate Config GeneratorBuild an /etc/logrotate.d file with schedule, compression, permissions and a reload script, then dry-run it with logrotate -d.
- fstab Entry GeneratorBuild a correct /etc/fstab line for disks, network shares, tmpfs and swap, with every field explained and common mistakes flagged.
- rsync Command BuilderBuild a safe rsync command for local or SSH copies, with excludes, bandwidth limits and a live explanation of the trailing slash rule.
- find Command BuilderCompose a find command from name, type, size, age, owner and permission filters, prune folders and pick an action.
- tar Command BuilderCreate, extract or list tar archives with gzip, bzip2, xz or zstd, and get the matching opposite command.
- GitLab CI GeneratorGenerate a modern .gitlab-ci.yml with stages, cache keyed on the lockfile, artifacts, rules, needs and a manual deploy job.
- Docker Command ExplainerPaste a docker command to see every flag explained in plain English, risky options flagged, and a host-to-container diagram of ports, mounts, network and env.
- Docker Compose VisualizerPaste a compose file to see its services, dependencies, networks, volumes and published ports as a diagram, with a plain-English summary of each service.
- Dockerfile Layer VisualizerPaste a Dockerfile to see its stages and layers, how stages copy from each other, and which layers a file change rebuilds.
- Docker Container LifecycleExplore the states a container goes through, the command behind every transition, the signals sent and what exit codes mean, then drive a demo container yourself.
- Cron Expression TesterDescribe a cron expression in plain English and list its next 10 run times in your timezone.
- Cron from Plain EnglishType a schedule in plain English and get the cron expression, broken down field by field.
- Terraform Plan VisualizerSee what a terraform plan will create, update, replace and destroy, grouped by resource with risky changes flagged
- Helm Values ConverterConvert a values.yaml into helm --set flags and back, with dots, commas, lists and strings escaped
- Nginx Location TesterFind which nginx location block matches a request URI and why, following the real matching order
- SSH Key FingerprintGet the type, size, SHA256 and MD5 fingerprints and comment of an OpenSSH public key
- IAM Policy VisualizerRead an AWS IAM or S3 bucket policy as allow and deny cards, with wildcard and public access risks flagged
- PromQL ExplainerBreak a PromQL query down step by step: selectors, ranges, functions, aggregations and vector matching
- iptables ExplainerRead iptables -L -n -v or iptables-save rules in plain English, chain by chain, with packet flow
- ps and top ExplainerExplain ps aux and top output: columns, process states and a sortable table of the heaviest processes
- Access Log AnalyzerAnalyze nginx and Apache access logs: status codes, top IPs and URLs, traffic chart, errors and bots.
- Cron to systemd TimerTurn a cron expression into systemd .timer and .service units, preview next runs, and convert OnCalendar back to cron.
CalculatorsBases, currency, units
- Developer CalculatorA calculator with hex, octal and binary modes.
- Currency ConverterConvert between currencies.
- Unit ConverterConvert length, weight, speed and other units.
- Aspect Ratio CalculatorFind an aspect ratio or the missing width or height.
- RAID CalculatorSee usable capacity, overhead, fault tolerance and relative speed for RAID 0, 1, 5, 6, 10, 50 and 60, compared side by side.
ProductivityStay focused while you build
DesignContrast, color, motion and icons
- WCAG Contrast CheckerCheck text and background contrast against WCAG AA and AAA.
- px, rem & em ConverterConvert px, rem, em, pt and percent, or a whole CSS snippet to rem.
- Cubic Bezier EditorShape a CSS easing curve with draggable handles and preview it.
- Image Color PaletteExtract the dominant colors of an image as HEX, RGB or HSL.
- Favicon GeneratorCreate favicon.ico, PNG sizes, Apple icon and a web manifest from a letter or an image.
- Color Shades GeneratorGenerate a Tailwind-style 50 to 950 shade scale from one color in OKLCH, with WCAG contrast for each shade and export as Tailwind config, CSS variables or a list.
- Color Blindness SimulatorRender your HTML or an image as people with protanopia, deuteranopia, tritanopia or achromatopsia see it.
- SVG Wave & Blob GeneratorGenerate SVG waves and blobs with sliders and a seed, then copy the SVG or a CSS background.
- Type Scale GeneratorModular type scale from a base size and ratio, exported as CSS, Tailwind or JSON.
- Font Pairing PreviewCurated Google Fonts heading and body pairs on a realistic article.
- Color Harmony GeneratorComplementary, analogous, triadic, tetradic and split palettes in OKLCH.
- OKLCH Color PickerPick colors in OKLCH, check sRGB and P3 gamuts, convert to hex, rgb, hsl and oklab.
- Design Tokens GeneratorColors, spacing, radii, shadows and type exported as CSS, Tailwind, DTCG JSON or SCSS.
- Glassmorphism GeneratorFrosted glass cards with backdrop blur, tint and border.
- Neumorphism GeneratorSoft UI shapes with paired light and dark shadows.
- SVG Path EditorEdit path data visually, convert absolute and relative, round and minify.
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