ASCIIFlow
asciiflow.com
Draws boxes and arrows as plain ASCII you can paste into a comment
No sign-upOn device
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The tabs a working developer never closes.
38 sites in this collection
asciiflow.com
Draws boxes and arrows as plain ASCII you can paste into a comment
bundlephobia.com
Shows what an npm package costs your bundle before you install it
caniuse.com
Answers whether a browser feature is safe to ship yet
codepen.io
Write HTML, CSS and JavaScript in a tab and watch it render live
crontab.guru
Translates a cron expression into a plain English schedule as you type
gchq.github.io
Chains encoding, hashing and decryption steps into a repeatable recipe
db-fiddle.com
Run a schema and a query against real MySQL, Postgres or SQLite
devdocs.io
One fast search box across a hundred API references, usable offline
diffchecker.com
Shows exactly what changed between two blocks of text, side by side
shell.duckdb.org
Run SQL over your own CSV or Parquet file without uploading it
excalidraw.com
Hand-drawn-looking whiteboard that opens instantly with no sign-up
aistudio.google.com
Prompt playground with model, temperature and system-prompt controls
hoppscotch.io
Sends HTTP, GraphQL and WebSocket requests from a browser tab
ipinfo.io
Tells you an IP address's owner, network and approximate location
jsoncrack.com
Turns a wall of JSON into a node graph you can pan and search
jwt.io
Decodes a JSON Web Token into readable header, claims and signature
mailtrap.io
Catches the emails your app sends in a fake inbox so no real person gets them
mermaid.live
Write a diagram as text and watch it render beside you
microlink.io
Turns any URL into a screenshot, a PDF or structured metadata
mockaroo.com
Generates realistic fake test data in CSV, JSON or SQL
mxtoolbox.com
Looks up MX, SPF, DKIM and DMARC records and names the one that is wrong
onecompiler.com
Compiles and runs code in around seventy languages with no sign-up
pagespeed.web.dev
Scores a page on real-user Core Web Vitals and lab measurements
pastebin.com
Drops a block of text or code at a short URL you can send to anyone
plantuml.com
Renders UML from a text description, with the source encoded in the URL
ssllabs.com
Grades a site's TLS configuration from A+ down to F and says why
regex101.com
Builds and explains a regular expression while you type it
securityheaders.com
Grades the HTTP security headers a site sends and names the missing ones
sequencediagram.org
Purpose-built editor for sequence diagrams, typed rather than dragged
sqlformat.org
Reformats an unreadable SQL statement into something reviewable
squoosh.app
Compare image compression settings side by side before you export
stackblitz.com
Runs npm install and a Node dev server inside the browser itself
stackedit.io
A Markdown editor with live preview that keeps working offline
tableconvert.com
Converts a table between CSV, JSON, Markdown, SQL and Excel
uuidgenerator.net
Hands you a fresh UUID on page load, single or in bulk
wave.webaim.org
Overlays accessibility errors directly on top of the page they affect
webpagetest.org
Loads your page from a chosen city and browser and films the result
whatsmydns.net
Checks a DNS record from dozens of resolvers around the world at once