Methodology

1. Inclusion criteria

• ▸The tool is publicly available and productively usable – not merely a waitlist.
• ▸It has an identifiable operator with legal or company details.
• ▸It provides standalone value and is not just a wrapper around someone else's model.
• ▸Its feature set is documented and comprehensibly described.
• ▸In scientific tiers: a solid methodological basis, disclosed data sources or peer-reviewed procedures.

2. Tier classification

Each tool is placed in the level that best describes its primary use case. Tools with several focus areas sit where they are most commonly used in practice; related alternatives are listed under “Similar tools” on each detail page. A level's width follows purely from the number of tools – it says nothing about quality or ranking. The levels themselves are grouped into seven thematic blocks: Assistance & Knowledge Work (levels 1–4), Creation & Media (5–7), Engineering & Operations (8–13), Business & Organisation (14–19), Science (20–23), Health & Environment (24–27) and Society & Culture (28–30). Each block has its own colour family and a divider row in the pyramid so related fields are recognisable at a glance.

3. Sources

• ▸Official product, pricing and documentation pages of the vendors
• ▸Privacy policies, data processing agreements and security whitepapers
• ▸Scientific publications and project pages of research institutions
• ▸Hands-on testing where free usage is possible

4. Privacy and language information

Privacy notes summarise what the vendor publicly documents: server location, handling of training data, data processing agreements and EU availability. Language details distinguish between interface and content. Neither replaces your own review before business use.

5. Pricing research & cost models

Pricing information comes from the vendors' official pricing and product pages. Every tool is assigned to one of four cost models: free (permanently usable without payment), open source (source code freely available, hosting optionally paid), freemium (a permanently usable free tier plus paid extensions) and paid (usable only against payment – a pure trial does not count as a free offering). This distinction corrects the common mistake of labelling freemium offerings as “free”.

In addition to the classification, a plan list is recorded for each tool: plan name, price in the vendor's currency, an approximate euro figure and notes on specifics such as usage-based billing, annual discounts, team or education plans. Extensive plan line-ups sit in a collapsible section on the detail page to keep it readable.

6. Filters & comparison

The filters on the start page derive directly from this researched data rather than from keywords in the description text. The pricing filter uses the four cost models; the “Free forever” toggle combines free, open-source and freemium tools – pure trials are excluded. The entry price reflects the cheapest paid monthly or per-user plan, grouped into up to €10, €10–30, over €30 and on request.

Purely usage-based prices – per token, credit, image or minute – are deliberately excluded from the entry price because they cannot be meaningfully compared with a monthly subscription; they appear in the plan list instead. Compare mode places collected tools side by side so cost model, privacy classification, languages and use case can be weighed directly. All filters and the comparison selection live in the URL and can therefore be shared.

7. Updates

The catalogue is revised continuously: new tools are added, discontinued services removed and descriptions updated when features, pricing or privacy terms change. In addition, automated checks regularly test every vendor link for availability and report anomalies such as dead links, redirects to unrelated domains or discontinued services. Those reports are reviewed manually before any entry is changed.

8. Limitations & independence

• ▸The catalogue is guidance, not a legal or security audit.
• ▸Pricing and features change fast in the AI market – the vendor is always authoritative.
• ▸Pricing is a snapshot: it can differ by region, currency, VAT and annual or education discounts. Euro figures for dollar-based plans are approximations.
• ▸The selection is curated and does not claim to be exhaustive.
• ▸There are no partnerships with the listed vendors, no affiliate links and no paid placements.