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Sync settings

Choose what your account keeps in step on every device where you are signed in.

  • My tools

    Always synced: the tools on your board, their order and size.

  • The windows open on your start page, including what you typed in them.

  • Every note in the notepad – on the notepad page, on your board and in windows.

  • Every list of website shortcuts – on the shortcuts page, on your board and in windows.

  • Every grid in the cover grid maker – on its page, on your board and in windows.

  • Every list of bookmarked organisations in the OIN lookup – on its page, on your board and in windows.

  • Keeps your pipeline and saved recipes on all your devices. Your files are never synced – only the steps and settings.

Turning something off removes it from your account straight away. Your devices keep their own copy.

Notifications

Tools that can tell you about something new while a Synsi tab is open, even when you are in another tab or app. Choose them for this browser.

This browser cannot show notifications from websites.
Notifications are blocked for this site. Allow them in your browser’s site settings (the icon left of the address), then switch them on here.

  • Says “New message” while a Synsi tab is open – never who wrote it or what.

Your choice is stored in this browser only. Notifications never show personal content such as a message or a number. They work while a Synsi tab is open; closed tabs get none.

Browse all tools →

Free online tools that just work

Count words, format JSON, convert units, calculate VAT and much more – instantly, privately and without signing up.

  • 100% free
  • No sign-up
  • Runs in your browser
  • Free API

My tools

Drag to rearrange · ✕ removes · ⤢ switches between icon and widget sizes · Esc or Done to finish.

Choose a background

Saved in this browser only. Your image is resized on your device and never uploaded.

Make Synsi your homepage

For your security, browsers don’t let websites change your homepage themselves. Setting it by hand takes less than a minute:

Google Chrome Your browser
  1. Open the menu ⋮ (top right) and choose Settings.
  2. Go to On startup and select “Open a specific page or set of pages”.
  3. Click “Add a new page”, paste the address above and click Add.
  4. Optional: under Appearance, turn on “Show home button” and enter the same address.
Microsoft Edge Your browser
  1. Open the menu … (top right) and choose Settings.
  2. Go to “Start, home, and new tabs”.
  3. Under “When Edge starts”, choose “Open these pages”, click “Add a new page” and paste the address above.
  4. Optional: turn on the Home button on the toolbar and enter the same address.
Mozilla Firefox Your browser
  1. Open the menu ☰ (top right) and choose Settings.
  2. Open the Home panel.
  3. Under “Homepage and new windows”, choose “Custom URLs…” and paste the address above.
Safari on Mac Your browser
  1. Choose Safari › Settings and open General.
  2. Paste the address above into Homepage.
  3. Set “New windows open with” to Homepage.
Chrome on Android Your browser
  1. Tap the menu ⋮ and then Settings.
  2. Tap Homepage, turn it on and choose “Enter custom web address”.
  3. Paste the address above.
iPhone and iPad Your browser
  1. Safari on iPhone and iPad has no homepage setting.
  2. Instead, tap the Share button and choose “Add to Home Screen” to open Synsi with one tap.

Tip: add the Web Search widget to My tools, and your homepage gives you search and your favourite tools in one place.

Make Synsi your start page

Pin the tools you use every day – as live widgets on this page or as icons in the dock – and open them in one click. Your board is saved in this browser; no account needed.

Adds web search, weather, a calendar, a notepad and a few popular tools. You can change everything later.

Popular to pin

All tools →

  • Web Search

    One search box for Google, Bing and DuckDuckGo: pick your search engine from the dropdown and search. Your query goes straight to the engine, never to us.

  • Weather

    Free weather forecast for any town or your current location: temperature, rain, wind and humidity now, hour by hour for 24 hours and for the next 9 days.

  • Calendar

    Free online calendar: today’s date, ISO week number, day of the year and quarter, month and year views with week numbers, plus public holidays for 5 countries.

  • Online Notepad

    Free online notepad that saves automatically in your browser. No sign-up, no server storage: write notes, count words and download them as a text file.

  • Word Counter

    Free online word counter: instantly count words, characters (with and without spaces), sentences, paragraphs and reading time. Private, no sign-up.

  • Percentage Calculator

    Free percentage calculator: find X% of Y, what percent X is of Y, the percentage change between two numbers, or add and subtract a percentage.

  • Unit Converter

    Free unit converter for 20+ categories including length, weight, temperature, volume, data storage, internet speed, pressure, energy, power, fuel economy and electrical units.

  • Password Generator

    Generate strong, random passwords with letters, numbers and symbols. Choose the length, exclude look-alike characters and see the entropy. Free and private.

  • No more tools found.

Your board is saved in this browser only.

Simple tools for everyday tasks

Synsi brings together small, focused online tools that each do one job well. Whether you are a writer checking the length of an article, a developer decoding a Base64 string, or a freelancer working out the VAT on an invoice, you get the answer immediately – without installing software, creating an account or wading through ads.

Private by design

Most of our tools run entirely in your web browser. The text, numbers and files you enter are processed on your own device and are never uploaded to our servers. That makes the tools fast, and it means you can safely use them with confidential documents, passwords or customer data.

A free API for developers

Every tool that can run on a server is also available through our free REST API, so you can automate the same calculations and conversions in your own applications. See the API documentation for endpoints, parameters and examples.