.gitignore generator
Gitignore generator combines baked official templates and custom patterns into a downloadable .gitignore.
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Developer
JSON, regex, hashes, JWT, YAML/XML, minify, cron, colours, gitignore, SQL, SVG tidy, and a CORS-bound API client—developer utilities that stay in the tab.
Runs in your browser · Nothing uploaded
- .gitignore generatorCombine official GitHub gitignore templates and download a .gitignore.Runs in your browser · Nothing uploaded
- Email validatorFormat and typo checks for one address or a pasted list. Not deliverability.Runs in your browser · Nothing uploaded
- SQL formatterPretty-print SQL in several dialects, entirely in the browser.Runs in your browser · Nothing uploaded
- SVG optimizerStrip fluff from an SVG and download a smaller file. Nothing is uploaded.Runs in your browser · Nothing uploaded
- REST / API clientBuild a request, fetch it from this tab, inspect the response. Subject to CORS.Runs in your browser · Nothing uploaded
- JSON formatterPretty-print, minify, and validate JSON, with the parse error's line and column.Runs in your browser · Nothing uploaded
- JSON ↔ CSVConvert a JSON array of objects to CSV and back, in the browser.Runs in your browser · Nothing uploaded
- Regex testerLive match highlights and capture groups for a pattern you type.Runs in your browser · Nothing uploaded
- URL encode / decodePercent-encode or decode a URL component, including Unicode.Runs in your browser · Nothing uploaded
- Base64 textEncode or decode plain text as Base64 (not the image tool).Runs in your browser · Nothing uploaded
- Hash generatorSHA-256, SHA-1, and optional WordPress (phpass) hashes of pasted text — all in this tab.Runs in your browser · Nothing uploaded
- Number base converterConvert between binary, octal, decimal, hex, ASCII bytes, and arbitrary bases 2–36 with BigInt.Runs in your browser · Nothing uploaded
- Unix timestamp converterTimestamp ↔ human date with auto seconds/ms detection, timezones, batch mode, and relative time.Runs in your browser · Nothing uploaded
- UUID generatorGenerate one or many version-4 UUIDs with crypto.randomUUID.Runs in your browser · Nothing uploaded
- JWT decoderSplit a JWT and pretty-print the header and payload. Does not verify signatures.Runs in your browser · Nothing uploaded
- File hashSHA-256 and SHA-1 of a file you drop here, via Web Crypto. Nothing is uploaded.Runs in your browser · Nothing uploaded
- YAML ↔ JSONConvert YAML to JSON and back in the tab with js-yaml.Runs in your browser · Nothing uploaded
- XML ↔ JSONConvert XML to JSON and back with DOMParser. Namespaces can be lossy.Runs in your browser · Nothing uploaded
- Minify / beautifyMinify or pretty-print HTML, CSS, or JavaScript without a network round-trip.Runs in your browser · Nothing uploaded
- Cron parserTurn a 5- or 6-field cron expression into plain English.Runs in your browser · Nothing uploaded
- Color converterHEX, RGB, HSL, and CMYK with a live swatch.Runs in your browser · Nothing uploaded
- Contrast checkerWCAG contrast ratio for two colors, with AA and AAA pass/fail.Runs in your browser · Nothing uploaded
- Chmod calculatorToggle rwx bits ↔ octal ↔ symbolic permissions.Runs in your browser · Nothing uploaded
- Subnet / CIDR calculatorIPv4 network, mask, broadcast, and usable hosts from CIDR.Runs in your browser · Nothing uploaded
- robots.txt generatorBuild a robots.txt with allow/disallow and optional sitemap.Runs in your browser · Nothing uploaded
- sitemap.xml generatorTurn a list of URLs into a sitemap.xml.Runs in your browser · Nothing uploaded
- PWA manifest generatorGenerate a web app manifest.json skeleton.Runs in your browser · Nothing uploaded
- llms.txt generatorDraft an llms.txt listing key pages for AI crawlers.Runs in your browser · Nothing uploaded
- JSON to TypeScriptInfer TypeScript interfaces from a JSON sample.Runs in your browser · Nothing uploaded
- curl to fetchConvert a common curl command to fetch() JavaScript.Runs in your browser · Nothing uploaded
- Keyboard testerPress keys to see which ones register, with key and code values.Runs in your browser · Nothing uploaded
- Gamepad testerSee button presses and stick values from a connected controller.Runs in your browser · Nothing uploaded
- HTTP status codesSearchable list of HTTP status codes with plain-English meanings.Runs in your browser · Nothing uploaded
- Keep screen awakeStop your screen from sleeping while this tab is open.Runs in your browser · Nothing uploaded
- Meta tags generatorFill in a form and copy the title, Open Graph, and Twitter meta tags.Runs in your browser · Nothing uploaded
- Mermaid diagram viewerWrite Mermaid text and see the diagram, then export SVG.Runs in your browser · Nothing uploaded
About Developer
Developer paste sites love accounts. This category is the jobs you do with configs, tokens, and snippets: format JSON, test a regex, hash a file, decode a JWT, convert YAML or XML, minify HTML/CSS/JS, explain cron, check contrast, assemble a gitignore, pretty-print SQL, tidy an SVG, or hit a public API from the browser.
The API tester is honest about CORS: browser fetch can only read APIs that allow it. Citation-style network honesty applies here too—no pretend “works with every API from a static site.”
Gitignore templates are baked at build time so the tool still works with wifi off after load. Image Base64 still lives under Convert; Base64 text here is for strings.
Tools in this category
Email validator
Email validator checks format and common domain typos for one address or a list. Not deliverability.
SQL formatter
SQL formatter pretty-prints with sql-formatter in the browser and a dialect picker.
SVG optimizer
SVG optimizer strips fluff locally and downloads a smaller SVG. Related to SVG convert under Convert.
REST / API client
REST / API client sends fetch from your browser, shows the response, stores history locally, and documents CORS limits.
JSON formatter
JSON formatter pretty-prints, minifies, and validates. When the input is invalid, you get a line and column, not a generic failure. It won't fetch a URL for you. Paste the document.
JSON ↔ CSV
JSON ↔ CSV turns an array of objects into CSV and back. Nested objects become a mess; flatten first if you care about columns.
Regex tester
Regex tester highlights matches and capture groups live. A worker timeout stops a catastrophic pattern from freezing the UI thread.
URL encode / decode
URL encode / decode percent-encodes or decodes a component, including Unicode. Use it for query values, not for inventing a whole URL layout.
Base64 text
Base64 text encodes or decodes strings, not files. For an actual image, use Image to Base64 under Convert.
Hash generator
Hash generator computes SHA-256 and SHA-1 via Web Crypto, plus optional WordPress phpass for offline DB password hashes.
Number base converter
Number base converter syncs binary, octal, decimal, hex, ASCII bytes, and arbitrary bases 2–36 with BigInt.
Unix timestamp converter
Unix timestamp converter does seconds/ms auto-detect, timezone display, batch paste, and relative time — all in the tab.
UUID generator
UUID generator mints version-4 UUIDs via crypto.randomUUID. Random IDs, not sequential database keys.
JWT decoder
JWT decoder splits a token and pretty-prints the header and payload. It does not verify signatures or fetch JWKS.
File hash
File hash computes SHA-256 and SHA-1 of a dropped file via Web Crypto. Bytes stay on your machine.
YAML ↔ JSON
YAML ↔ JSON converts configs both ways with js-yaml locally. Exotic YAML tags may not round-trip.
XML ↔ JSON
XML ↔ JSON uses DOMParser in the tab. Namespaces and mixed content can be lossy on a round trip.
Minify / beautify
Minify / beautify pretty-prints or shrinks HTML, CSS, and JavaScript here. Not TypeScript; broken syntax returns an error.
Cron parser
Cron parser turns a five- or six-field expression into plain English. Explain-only; it won't compute next run times.
Color converter
Color converter translates HEX, RGB, HSL, and CMYK with a live swatch. CMYK is math from RGB, not a press ICC profile.
Contrast checker
Contrast checker reports the WCAG ratio for two colors and AA/AAA pass or fail. Opaque sRGB only.
Chmod calculator
chmod calculator toggles rwx bits and shows octal and symbolic modes side by side. Three-digit modes only, no ACLs.
Subnet / CIDR calculator
Subnet calculator gives the network address, mask, broadcast, and usable hosts for an IPv4 CIDR. IPv4 only.
robots.txt generator
robots.txt generator writes allow/disallow rules and an optional sitemap line. It is a text file you host; it cannot enforce access control.
sitemap.xml generator
Sitemap generator turns a list of URLs into a basic sitemap.xml. It does not discover pages or submit anything to search engines.
PWA manifest generator
Manifest generator writes a PWA manifest.json skeleton with name, colours, display mode, and icon placeholders. It does not resize icons.
llms.txt generator
llms.txt generator drafts an llms.txt listing key pages. It is an optional convention, not a ranking promise.
JSON to TypeScript
JSON to TypeScript infers interfaces from one JSON sample. The types are a best-effort starting point, not a validator.
curl to fetch
curl to fetch converts common curl flags into a fetch() call. It does not run the request and does not support every curl flag.
Keyboard tester
Keyboard tester lights up keys as you press them and shows key, code, and modifier values. The OS may swallow some combinations before the browser sees them.
Gamepad tester
Gamepad tester shows button and axis values from a connected controller. Press a button first so the browser reports the device.
HTTP status codes
HTTP status codes is a searchable reference with short meanings and the common unofficial codes marked. It is a reminder, not the RFC.
Keep screen awake
Keep awake asks the browser for a screen wake lock while the tab is visible. It keeps the screen on, not the whole system, and needs Wake Lock support.
Meta tags generator
Meta tags generator turns a short form into title, description, Open Graph, and Twitter card tags. It does not check that your image URL loads.
Mermaid diagram viewer
Mermaid viewer renders diagram text as you type and exports SVG. Syntax follows the Mermaid version bundled with the site.
Common questions
Does the API client proxy through your server?
No. Requests go from your browser to the URL you enter. CORS is enforced by the browser.
Does the JSON formatter send my payload to a linter API?
No. Parse and pretty-print run in the tab. If the JSON is a production config or a customer export, that's why this page exists instead of a pastebin.
Are gitignore templates live from GitHub?
No. They are baked into static JSON when the site builds.
Does email validation prove an inbox exists?
No. Format and typo hints only.
Why these tools don't upload your files
There is no server to upload to. Each page is a static file, and the work happens in your browser. Your file is read from disk into memory, processed, and handed back as a download. Once the page has loaded you can disconnect from the network and it keeps working. The longer explanation