Edit an invoice, look up who hosts a domain, shrink an image, turn JSON into a spreadsheet, run a SQL query or catch a one-time passcode. Each one opens in a second and does a single job properly.
Free to use · Most tools run on your own device · Nothing to install
The things people open KRHTech for most often. Each one drops you straight into the right screen.
Seven tools, grouped by the kind of work they belong to. Nothing here asks you to create an account before you can see what it does.
Open a PDF, a scanned page or a chart, then drop editable text fields on top of it — invoice number, line items, totals, a signature line. Drag each field where it belongs and export a clean, flattened copy that looks like it was typed that way.
Type a domain and get its A record, the IP behind it, the hosting provider and a rough location. It also makes a best-effort guess at the technology stack the site runs on, which is handy when you inherit a project with no documentation.
Drop in any image and export it as PNG, JPG or WebP with a quality slider you can actually see the effect of. Converting a photo to WebP at around 80% quality usually cuts the file in half with no visible difference, which is the single cheapest thing you can do for page speed.
Paste data in one shape and pull it out in another — JSON to CSV for a spreadsheet, CSV to a JavaScript array for a prototype, a messy list into clean key-value pairs. It handles nested objects by flattening them into dotted column names.
Write HTML, CSS and JavaScript side by side and watch the preview update as you type. Useful for testing a snippet from a tutorial, checking a CSS idea, or proving a bug before you take it back to a real codebase.
A scratch SQLite database that lives in the tab. Create a table, insert a few rows and practise joins, grouping or window functions without installing anything. When you close the tab the database goes with it, so there is nothing to clean up.
Generate a disposable inbox, paste it into whatever sign-up flow you are testing, and the rig reads the one-time code out of the message the moment it lands. It saves the loop of switching to your real mail client on every test run.
No tools in that category yet.
No onboarding, no trial countdown, no email verification before you can see the interface.
Open the tool that matches the job from the grid above or the menu in the header. Everything loads in one page, so there is no dashboard to navigate first.
Drag a file onto the page or paste your text straight in. For the converters and editors the work happens in your browser, so large files do not wait on an upload.
Download the finished file or copy the output. Close the tab and nothing is left behind — there is no history page, because there is no history.
Most online converters are a thin page in front of someone else's server. KRHTech does the work on your own machine wherever the job allows it, which changes three things that matter.
An image you convert or a spreadsheet you reshape never crosses the network. There is no copy sitting on a server waiting to be deleted, because no copy was made.
Converting a 30 MB image usually means waiting twice — once to send it up and once to pull it back. Doing it locally removes both waits and the free-tier queue that normally sits between them.
A domain lookup and a temporary inbox cannot work offline — they need a server by definition. Those two are marked clearly rather than dressed up as private.
A small set of utilities built by one team, kept free, and maintained because we use them ourselves.
KRHTech started as a folder of throwaway scripts. One of us kept needing to put an invoice number onto a supplier's PDF. Another kept pasting JSON into a spreadsheet by hand. Every time we searched for an online tool to do it, we landed on a page carrying six banners, a mandatory sign-up and a queue for the free tier. So we built the plain version instead, and then kept building.
The rule for adding a tool is simple: it has to be something we reached for twice in a month, and it has to do one job without a settings page. That is why there are seven tools here rather than seventy. A directory of half-working utilities is not more useful than a short list of ones that work.
KRHTech is free to use and is funded by advertising. Ads are placed between sections of a page, never over a tool's working area, and never in a way that makes a download button harder to find. We do not sell, rent or share the files you process, and the tools that run locally have no file to share in the first place.
The same handful of situations come up again and again.
The invoice editor is the most-used tool on the site, mostly by people who receive a PDF template from a client and need to fill it in properly rather than printing, writing on it and scanning it back.
The domain checker, the code editor, the SQL scratchpad and the OTP rig cluster around the same working day. The OTP rig in particular exists because testing a sign-up flow forty times in an afternoon is miserable with a real inbox.
The SQL editor is used heavily around exam season. Practising joins usually means installing a database first, and on a shared or locked-down machine that is often not an option. A scratch database in a browser tab removes the obstacle.
Government portals, job applications and university forms all cap uploads at awkward numbers. The image converter's quality slider is usually the fastest way under a limit without the result looking rough.
If something here is not covered, the contact details are just below.
Yes. Every tool on this site is free, and most need no account at all. You can open a tool, finish the job and close the tab without signing up or handing over an email address. The site is funded by advertising rather than subscriptions.
For the image converter, the text format converter, the code editor and the SQL editor, the work happens inside your browser on your own device, so the file never leaves your computer. The domain checker and the email test rig need a network lookup by definition, so those do send a request to a server. We would rather say that plainly than claim everything is private when it cannot be.
There is no fixed cap. Because processing runs on your own device, the practical limit is your available memory rather than a plan tier. Files in the tens of megabytes are comfortable on most modern phones and laptops. Very large files on an older phone may be slow, and closing other tabs usually helps.
Yes. Every tool is built to work on a touch screen down to roughly 320 pixels wide. The document editor and the SQL editor are easier on a larger screen simply because they show more of your work at once, but both are usable on mobile.
Yes. Anything you create or convert here is yours, including invoices you send to clients and images you publish. KRHTech claims no rights over your input or your output and keeps no copy of either.
A temporary inbox is short-lived by design and is meant for QA and sign-up testing only. Treat anything sent to it as readable and disposable. Do not use it for an account you intend to keep, and never for banking, government or workplace identity.
For photographs on a website, WebP at around 80% quality is usually the best trade, often halving the file with no visible loss. Use PNG when you need a transparent background or crisp flat graphics such as a logo or a screenshot of text. Use JPG when something old in your workflow refuses to accept anything else.
A real person reads these. Expect a reply within two working days.
Something broken, or a file that will not convert? Tell us the tool, the browser and what you expected to happen.
Questions about what we store, what advertising partners collect, or how to opt out of personalised ads.
If you have reached for the same missing utility more than once, that is exactly the kind of thing we want to hear about.