Every developer has a set of micro-tasks that aren't worth context-switching for, but annoying enough to break flow: you need a placeholder image to fill a card, you need to decode a Base64 string, you need to check what Unix timestamp 1743532800 maps to. You end up Googling, landing on a cluttered site full of ads, and losing 2 minutes to something that should take 5 seconds.
We got tired of it. So we built small, focused tools that do exactly one thing and get out of the way.
All four are free at skybin.io/free-tools — no login, no sign-up, no upsell.
FauxImage — Placeholder Images on Demand
When you're building a UI and the real images aren't ready yet, you need filler. FauxImage generates placeholder images at any dimension you specify:
https://faux.skyb.in/400x300
https://faux.skyb.in/1200x630
Drop that URL directly into an <img> tag or anywhere you'd use a real image. It works in HTML, CSS backgrounds, Markdown, and Figma imports. No download required, no colour customisation ceremony — just dimensions and you're done.
Base64 — Encode & Decode in One Click
Paste in a string, get Base64 out. Paste in Base64, get the decoded string out. That's it.
It handles both encode and decode in the same interface, recognises which direction you need automatically, and copies to clipboard immediately. Useful for:
- Inspecting JWT payloads (the header and payload segments are Base64url-encoded)
- Checking what's inside a
data:URI - Debugging API responses that encode binary data
- Generating encoded credentials for Basic Auth headers
Epoch — Unix Timestamp Converter
Paste in a Unix timestamp, get a human-readable date. Pick a date, get the timestamp back. The tool shows the result in UTC and your local timezone simultaneously, which removes the mental arithmetic of working across time zones.
Comes up more often than you'd think:
- Reading database records where
created_atis stored as an integer - Setting expiry times in JWTs or cache headers
- Debugging log files from servers in a different timezone
- Converting user input dates to timestamps for API calls
JSON Tools — Format, Validate & Minify
Three operations on JSON from a single interface:
Format takes compact or malformed-looking JSON and pretty-prints it with consistent indentation — useful for reading API responses or config files that arrived as a single line.
Validate tells you immediately if your JSON is syntactically valid, and if not, points to where the problem is. Saves the round trip of pasting into your editor and waiting for the linter.
Minify strips whitespace and produces the smallest valid JSON representation — helpful before embedding JSON in a script tag or sending in a request body where size matters.
Where to Find Them
All four tools live at skybin.io/free-tools. No account required, no usage limits, no tracking pixels. We built them for our own daily use and put them online in case they're useful to anyone else.
If there's a small utility you find yourself reaching for regularly that isn't here, let us know at [email protected] — we're always open to adding more.