Skip to content
This page is also available in your language. Switch

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 →

Developer tools

Encoders, formatters and generators for everyday development work – in the browser and via a free API.

Base64 Encode & Decode

Encode text to Base64 or decode Base64 to text online. Full UTF-8 support and URL-safe Base64URL option. Free, instant and private. Also via API.

URL Encode & Decode

Percent-encode text for safe use in URLs and query strings, or decode encoded URLs back to readable text. UTF-8 support. Free online URL encoder.

JSON Formatter & Validator

Format, beautify, minify and validate JSON online. Choose 2 spaces, 4 spaces or tabs, and get clear error messages for invalid JSON. Free and private.

Social Media Preview

Preview how a page link may look in a social post. Check its Open Graph and Twitter Card title, description and image.

Hash Generator

Generate MD5, SHA-1, SHA-256, SHA-384 and SHA-512 hashes of any text instantly. UTF-8 input, uppercase option, runs in your browser. Also via API.

UUID Generator

Generate random UUID v4 or time-ordered UUID v7 identifiers online, in bulk up to 500 at once. Uppercase and no-hyphen options. Free, also via API.

SSL Certificate Checker

Free SSL certificate checker: see a domain's chain, expiry, SANs, issuer and trust, or decode a PEM certificate – PKIoverheid and UZI too.

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.

OIN Lookup

Find the OIN (Organisatie-identificatienummer) of a Dutch government body or company by name, OIN or KvK number. Shows sub-OINs, status and BSN authorisation.

eID 4.4 SAML Validator

Validate DV or LC SAML metadata against eID SAML 4.4: XML schema, signature, PKIoverheid certificates, OIN, entityID, endpoints and algorithms. Free, nothing stored.

eTD Service Catalogue Editor

Load an OIN's entries from the eTD service catalogue, edit service definitions, instances, attributes, classifiers and certificates, and generate checked catalogue XML. Free.

Small utilities you reach for every day

Decoding a token, pretty-printing an API response, generating test IDs or a strong password: these tasks come up constantly during development. Instead of searching for a one-off script, keep this page bookmarked.

Every developer tool runs client-side, so secrets such as tokens and passwords never leave your machine. When you need the same functionality in a pipeline or backend, use the matching endpoint of the free Synsi API.