About LogicUtil

LogicUtil is a collection of 12 free developer utilities built around one idea: the small, repetitive tasks you handle every day should not require an account, a subscription, or your data.

How it works, and why that matters

Every tool on this site, the image converter included, runs as JavaScript inside your own browser. The text you paste is processed on your machine and never travels over the network. You do not have to take that on trust — open your browser's network panel, paste a large payload into any tool, run it, and watch that no request leaves the page. Once a tool has loaded, it keeps working with the connection switched off.

This is the whole point rather than a nice extra. The data a developer most often needs to format, decode or hash is precisely the data they are least free to hand to a stranger: a production API response, an access token, a customer record, a config file with credentials in it. A tool that posts your input to a server is unusable for exactly the cases where you need it most.

That includes the Image Converter. Images are decoded and re-encoded with the canvas APIs built into your browser, and a batch download is zipped inside the page, so even a private photo never leaves your device. The Privacy Policy covers the detail.

What is here

The full list lives on the all tools page.

Every tool ends with a reference article

A tool that only does the thing is half a tool. Each page here closes with a long-form article about the format itself: what it is, how it is built, the mistakes that actually happen in practice, and how it relates to the neighbouring tools. Why Base64 output is exactly a third larger than its input. When to reach for UUID v7 instead of v4. Why hashing a password with SHA-256 is a bug rather than a shortcut. The tool solves today's problem; the article is so you do not have to look it up again next month.

No account, no advertising, no limits

There is no sign-up, no email to hand over, no free tier with features held back, and no cap on how much you can use any tool. The site carries no advertising and no ad-network scripts. Visits are counted by the site's own cookieless statistics, which store no IP address and cannot identify you, and by Google Analytics, which loads only after the page has finished loading and asks visitors in Europe first. The Privacy Policy has the details.

LogicUtil exists because too many "free" online tools bury a thirty-second task under a sign-up wall, an ad block, or an arbitrary usage limit. Here you open the tool and get to work.

Languages

The site is published in eight languages — English, German, Spanish, Portuguese, French, Persian, Arabic and Japanese — with Persian and Arabic laid out right to left. English lives at the root and every other language under its own prefix, so the German JSON formatter is at /de/tool/json-formatter. The tool interfaces, the reference articles and the category guides are all translated rather than machine-swapped.

There is also a machine-readable summary of the site for language models, following the llmstxt.org convention and generated from the same data as the site itself, so it never drifts from what is actually published.

Who is behind LogicUtil

I am Saman, a web developer. I studied computer science, have worked with computers for about fifteen years, and have spent the last eight of them building web applications with PHP, JavaScript and MySQL.

The idea for this site sat in my head for a long time. The online tools I opened every day were covered in advertising, sent whatever I pasted to somebody else's server, or stopped working until I created an account. I wanted one place that was free, simple and professional, without limits and without problems - so I built it. It took about a year of evenings, and it went live on its own domain in mid-2026.

The site is plain PHP and vanilla JavaScript, with no framework and no build step, which is part of why every tool loads instantly and runs in your browser. Found a bug, miss a tool, or just want to say hello? Write to [email protected] - I read every message.

What is next

New tools get added based on what developers actually reach for day to day, and existing ones get deepened rather than left at the minimum that works. If a tool here is missing an option you expected, that is usually worth saying — it is the most direct way the list of what to build next gets set.