About ToolStack Hub

ToolStack Hub is a collection of free online tools that run in your web browser. We built it so that everyday jobs, such as compressing a photo, merging PDFs, formatting JSON or working out VAT, take seconds and do not require an account.

Private by design

Our tools process files and text on your device. We do not upload your content to our servers and we do not keep copies. That makes the tools fast and suitable for sensitive documents.

How we make money

The tools are free. The site is supported by advertising, which helps pay for hosting and for building new tools. We keep ads clearly labelled and away from the controls you use.

What is on the site

ToolStack Hub covers text and writing tools, image and PDF utilities, developer tools such as formatters and encoders, SEO and social media generators, unit and date converters, and money calculators. The money section includes salary calculators for 11 countries and VAT, GST and sales tax calculators for 31 countries, plus UK-specific tools such as income tax, stamp duty and mortgage calculators.

How we build and check the tools

Every calculator is written as plain code that you can run in your browser. Before a tool goes live we run it against known results: for tax tools, benchmark figures from official guidance and independent calculators, and for conversions, the exact definitions of the units. We also run automated tests that exercise every tool with typical and edge-case inputs.

Tax and salary tools use the rates for the current tax year and state the year on the page. They model a single employee on standard terms. Regional rates, tax codes, pension schemes, allowances and benefits in kind change real pay, so treat the results as estimates and confirm important figures with your tax authority or an adviser.

Where our figures come from

Rates and thresholds come from official sources such as GOV.UK and HMRC for the UK, the IRS for the United States, the Canada Revenue Agency, the Australian Taxation Office, Revenue (Ireland), the German Federal Ministry of Finance, the French and Spanish tax agencies, the Inland Revenue Authority of Singapore, SARS in South Africa and Inland Revenue in New Zealand, and equivalent national VAT and GST authorities. We review them each year when new budgets take effect, and sooner if a rate changes.

Our AI and news content

Some tools, such as caption and title generators, use an AI model to draft text. We label these tools and you should review the output before using it. Our news digest summarises stories from named publishers, links to every original article and is clearly marked as an automated summary. It is not a substitute for reading the sources.

Corrections

If you find a wrong figure or a broken tool, tell us through the contact page. We fix confirmed errors quickly and update the page.

Get in touch

Spotted a mistake or want a new tool? Visit the contact page.