Free tools
Small tools that do one thing well
27 free utilities for links, QR codes, campaigns and the everyday work around them. Most run entirely in your browser. A free MASK account unlocks the results, and MASK is where the ones worth keeping live.
Most used
- Link ShortenerTurn a long URL into a short one you can share anywhere.Links & URLs
- QR Code GeneratorMake a QR code for any link, ready to download.QR codes
- QR Code DesignerStyle a QR code with your colours, shapes and logo.QR codes
- Wi-Fi QR Code GeneratorNewLet guests join your Wi-Fi by scanning instead of typing the password.QR codes
- UTM BuilderTag a campaign URL so your analytics can tell where traffic came from.Marketing
- Ad Metrics CalculatorNewWork out CTR, CPC, CPM, CPA, ROAS and ROI from the numbers you already have.Marketing
- Bio Link BuilderBuild the one link that holds all your other links.Social & creator
- WhatsApp Link GeneratorMake a click-to-chat link with the first message already written.Social & creator
- Image ResizerNewResize an image to the shape you need, without uploading it.Images
- JSON Formatter & ValidatorNewFormat messy JSON, or find out exactly where it breaks.Developer
27 tools shown
Links & URLs
Build, shorten and control the links you share.
- Link ShortenerTurn a long URL into a short one you can share anywhere.Links & URLs
- Bulk Link ShortenerShorten up to 20 URLs at once instead of one at a time.Links & URLs
- Smart Link BuilderSend iOS, Android and desktop visitors to different destinations.Links & URLs
- Expiring Link GeneratorShare a link that stops working after a date or a click limit.Links & URLs
- URL Encoder & DecoderNewPercent-encode or decode a URL component without guessing the rules.Links & URLs
QR codes
Generate and style QR codes for print and screen.
- QR Code GeneratorMake a QR code for any link, ready to download.QR codes
- QR Code DesignerStyle a QR code with your colours, shapes and logo.QR codes
- Bulk QR GeneratorGenerate a batch of QR codes from a list of links in one go.QR codes
- Wi-Fi QR Code GeneratorNewLet guests join your Wi-Fi by scanning instead of typing the password.QR codes
- vCard QR Code GeneratorNewPut your contact details on a card people can scan to save.QR codes
Marketing
Tag campaigns and work out what the numbers mean.
- UTM BuilderTag a campaign URL so your analytics can tell where traffic came from.Marketing
- Campaign PlannerKeep UTMs consistent across every link in one campaign.Marketing
- Ad Metrics CalculatorNewWork out CTR, CPC, CPM, CPA, ROAS and ROI from the numbers you already have.Marketing
- Engagement Rate CalculatorNewMeasure engagement against followers, reach or impressions — and say which you used.Marketing
Social & creator
Everything that goes in a bio, a post or a profile.
- Bio Link BuilderBuild the one link that holds all your other links.Social & creator
- Social Profile Link BuilderBuild clean, correct links to any social profile.Social & creator
- WhatsApp Link GeneratorMake a click-to-chat link with the first message already written.Social & creator
- Email Signature GeneratorBuild an HTML signature that survives being pasted into a mail client.Social & creator
- Link Preview CheckerSee how your link will look when someone shares it.Social & creator
- Character & Word CounterNewCount characters, words and lines before you hit a limit.Social & creator
Images
Resize and prepare images without uploading them anywhere.
Developer
Small, exact utilities that run entirely in your browser.
- JSON Formatter & ValidatorNewFormat messy JSON, or find out exactly where it breaks.Developer
- Base64 Encoder & DecoderNewEncode or decode Base64 text without mangling non-English characters.Developer
- Unix Timestamp ConverterNewTurn an epoch number into a date, and a date back into an epoch.Developer
- UUID GeneratorNewGenerate version 4 UUIDs from your browser's cryptographic randomness.Developer
- Hash GeneratorNewCompute a SHA-256, SHA-384 or SHA-512 digest of any text.Developer
Files & data
Convert between the formats that spreadsheets and APIs speak.
The tools are free. MASK is where the results live.
A link you can re-point after sharing it. A QR code you can change once it is printed. A bio page that holds everything, on your own domain — with the numbers to show what people actually clicked.