Security
Passwords, passphrases and the random strings everything else is built from.
A toolbox that lives in your browser
Twenty small tools.
Twenty small tools.
Zero sign-ups.
EduTray is a tray of single-purpose utilities for everyday jobs: making a password, shrinking a photo, checking a colour, tidying up JSON, comparing two texts. Open the one you need, use it, close the tab.
- No account needed
- Files never uploaded
- Works offline
The tray
Pick a shelf, grab a tool
Twenty tools in five groups. Each one is its own page with its own job — nothing to configure, nothing to learn first.
Images
Shrink, resize, convert and package pictures before they go anywhere.
Colour
Pick colours, check contrast and build palettes and gradients.
Data
Reformat, convert and encode structured data without a fuss.
Text
Count, convert, compare and fill words before they go out.
Featured
Five tools, up close
A small taste of what's on the tray — each card below shows a real piece of the tool's interface, not a mockup. Open any of them and you're using it within seconds.
Security
Password Generator
Truly random passwords with no modulo bias, an honest entropy readout, and a crack-time estimate that updates as you drag the length slider.
k7#Vm2qLz$9WpXr4@nT
Fortress~121 bits
Images
Image Compressor
Drop in a photo, pick JPEG, WebP or PNG, drag the quality slider — and see the before/after sizes side by side before you keep anything.
Colour
Colour Studio
One colour read back as HEX, RGB and HSL at once — or picked straight off your screen.
#2DD4BF
rgb(45, 212, 191)
rgb(45, 212, 191)
Data
JSON Formatter
Beautify, minify or sort the keys — and when something's wrong it names the line and column.
{
"build": 42,
"pass": true
}
"build": 42,
"pass": true
}
✓ Valid · 2 keys · 0 problems
Text
Diff Checker
Paste two versions, get a clean line diff. Side-by-side view and whitespace options included.
"private": true,- "node": ">=18",+ "node": ">=20", "license": "MIT"
Fifteen more on the tray
Passphrase Generator · Hash Generator · UUID Generator · Image Resizer · Image Converter · Favicon Generator · Contrast Checker · Palette Generator · Gradient Generator · JSON to CSV · Base64 Encoder · URL Encoder · Word Counter · Case Converter · Lorem Ipsum Generator
Anatomy
Learn one page, you've learned them all
Every tool page is laid out the same way, on purpose. The second tool you open already feels familiar.
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01 The head
The tool's name and the path back to its shelf. Nothing above it except the site header — no popups to dismiss, no banners to accept, no sign-in wall.
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02 The settings
Whatever the tool needs to know first: a length, a quality, a format, a delimiter. They always sit in the same place, so the third visit is faster than the first.
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03 The output
The result, with copy and download right next to it. It shows up as soon as there is something to show and follows your settings as you change them.
In practice
Whole jobs, start to finish
Nobody wakes up wanting a tool — they have a job that happens to need two or three of them, in an order that matters. These are the runs that come up most often.
A photo that has to go on a page
Straight off a phone, a picture is around 4 MB and far wider than any layout. Fix the size first, the weight second — the other way round costs quality you can't get back.
- Image Resizer — down to the width the layout actually uses
- Image Compressor — at the finished size, so the quality slider means what it says
- Favicon Generator — cut from the finished file, not the 4 MB original
A brand colour that fails contrast
The colour works as a logo and fails as body text. The hue was handed to you and isn't yours to change — so you move along the one axis you have.
- Contrast Checker — test the exact pair you plan to ship, at the sizes you'll use
- Colour Studio — walk the lightness down until it clears the bar, hue untouched
- Palette Generator — build the rest of the set around the shade that passed
A config file that has to survive the trip
Something in the file is wrong and you're not sure what — and it has to travel through a channel that mangles quotes and strips newlines.
- JSON Formatter — a stray comma is obvious at four-space indentation and invisible at none
- Diff Checker — read what actually changed, not what you remember changing
- Base64 Encoder — so it arrives as the same bytes that left
Choosing
Two tools, one job — which one?
The pairs people mix up most. Each one has a single deciding question; the longer explanation lives in the notebook.
Compressor or resizer?
Too many bytes for the connection → compress. Too many pixels for the layout → resize.
The compressor keeps the dimensions and discards detail; the resizer changes the dimensions and keeps what detail it has. Run them in the wrong order and the quality setting lies to you.
Why the order mattersHash or UUID?
Same input, same string every time → hash. A fresh name for something unnamed → UUID.
Use a hash to check whether a file changed in transit. Use a UUID when you need an identifier with nothing to derive it from — and nothing to guess it from either.
Which UUID version you wantBase64 or URL encoding?
Binary through a text-only channel → Base64. Text through a query string → URL encoding.
The wrong one doesn't fail loudly — it just makes the output longer, uglier, and wrong in a way that only surfaces on a stricter server than the one you tested.
What Base64 is (and isn't)Passphrase or password?
Long and typable from memory → passphrase. A short random string for a manager → password.
Five ordinary words usually carry more entropy than eight characters of symbol soup — and you stand a chance of typing them without reaching for the clipboard.
The honest comparison
Limits
Where each tool stops
A tool that claims to have no edges is selling you something. These are the edges — the point past which you should reach for something else.
Password Generator
The strength figure counts the size of the search space, assuming the attacker knows the recipe but not the result. That's arithmetic, not a promise — it can't know whether you pasted the password into a chat window afterwards, or typed it on a machine you don't control.
Image Compressor
Lossy means gone. Every re-encode of a JPEG costs a little quality and no setting gets it back, so keep the original until the compressed copy has actually shipped — don't compress the same photo again for each new size.
Hash Generator
A fingerprint, not a vault. MD5 and SHA-1 have known collisions, so treat their digests as checksums rather than guarantees — and never store passwords with a fast hash. Password storage needs a deliberately slow function, which a page that must answer instantly is the wrong place to run.
Base64 Encoder
Not encryption. Anyone holding the output can decode it in one line, with no key involved at any point. It exists to carry binary through channels that only accept text — treat the output as readable, because that's what it is.
Word Counter
It depends on who's counting. This one counts whitespace-separated tokens; a word processor counts differently and will disagree on hyphenated words, numbers and apostrophes. Text with no spaces between words has no tokens to count at all — a long-running disagreement, not a bug.
Contrast Checker
The maths runs on the hex values you type in, so the same pair scores identically on a calibrated monitor and on a dim laptop in a bright room. The number is the part that travels; what you see on your own screen is not.
JSON Formatter
Sorting the keys changes the file. The meaning survives reordering, but the bytes don't — if that JSON is signed, hashed or compared against another copy, the sorted version won't match, and nothing will warn you because from the tool's side nothing went wrong.
URL Encoder
Percent-encoding isn't one rule: a space is a plus sign in a query string and %20 in a path, and several characters are safe in one position but not the other. Encode for the wrong position and you get a link that works — right up until it meets a stricter server.
The longer version — licences, warranty, and where the advice stops — is on the disclaimer page.
From the notebook
The questions the tools raise
Every article takes one of them and answers it properly — the arithmetic shown rather than summarised, with the tool that does the job at the end.
Passphrase or password: which should you actually use?
Real words in a row versus random characters — how the two compare on strength, memory and everyday usability.
Lossy vs lossless compression: what you're actually trading
The one decision behind every image file size — what gets thrown away, what stays, and when it matters.
HEX, RGB and HSL: three ways to say the same colour
What each notation means, how to read one at a glance, and when to reach for each.
How it's built
Simple on purpose, private by design
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Fast because there's less
No frameworks, no trackers, no chat widgets. Just HTML, CSS and plain JavaScript, so every page is ready the moment it loads.
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Your stuff stays yours
Passwords are generated, images are processed and text is converted entirely on your device. Open your browser's network tab and watch: nothing is ever sent anywhere.
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One page, one job
No dashboards, no projects, no onboarding tour. Each tool does the thing you came for and stays out of the way while it does it.
Questions
Short answers to fair questions
Do my files or passwords leave my device?
No. There is no server behind EduTray. Images are read with the File API and drawn to a canvas locally; passwords come from your browser's own secure random generator. Nothing is transmitted, stored or logged.
Is it really free?
Yes. Every tool is free to use with no limits, no watermarks and no account. The site may carry advertising in the future to cover hosting — any ad code runs in the page around the tools and has no access to anything you type or drop into one.
Does it work offline?
Once a page has finished loading, yes. Every tool is self-contained, so you can even save a page to your computer and open it later without an internet connection.
Which browsers are supported?
Any recent Chrome, Edge, Firefox or Safari. A couple of newer features — like picking a colour straight off your screen — only work in Chromium-based browsers, and the relevant tools say so on the page.
Can I use the output commercially?
Yes. Passwords, palettes, compressed images, converted files — whatever you make here is yours. No watermark, no licence claim, no attribution needed.
How do I suggest a tool or report a bug?
Through the contact page. Bug reports are most useful with the browser name and version, what you did, and what you expected instead.
Start with any tool.
No forms to fill, nothing to install. Pick a shelf above — or search for exactly what you need.