Thunderstock
Thunderstock is a Dutch AI merchandise planning platform for fashion brands and non-food retailers. Five engines cover budgeting, buying, stock, logistics and markdown pricing, forecasting demand at SKU level to cut missed sales and overstock.
What is Thunderstock?
Thunderstock is a web-based merchandise planning platform aimed at fashion brands and non-food retail chains, published by Thunderstock BV in Diemen, the Netherlands. The site calls it the Ahead of Time Machine: a single system meant to replace the spreadsheets, the last-minute transfers and the guesswork that usually sit behind a well-presented collection.
The platform is organised into five engines, each covering one stage of the product life cycle. Strategy handles everything decided before the season starts, aligning the financial, sales and product sides of a budget; it offers collaborative budgets with version control that merges every contributor's changes into one master version, open-to-buy and intake planning, and WSSI monitoring once the season is running. Buy supports collection building, first orders and reorders for new and existing articles, and pack optimization. Stock governs movement: allocation and replenishment, transfers and consolidation between stores, and channel planning across physical and online sales. Logistics works on flow rather than product, with load estimation, load balancing and route optimization inside the retailer's logistical capacity. Pricing closes the cycle by reducing end-of-season overstock while protecting lifetime margin, through markdown budgets, markdown proposals and promotion analysis.
Underneath all five sits demand forecasting at SKU level, granular enough to distinguish variant, colour and size in a single store. The intended users are named on the site itself: merchandisers, buyers, planners and stock controllers. Access is through a browser application reached from the Login link in the main menu; there is no desktop client and no mobile app.
The vendor's stated design principle is Human Before Artificial, which it explains as no black boxes and no robot talk, but transparent logic and recommendations that hold up in a merchandising meeting. Proposals such as store transfers are put forward for approval rather than executed silently. A separate documentation site exists, with release notes issued regularly, though it is entirely behind a login. On its Cases page the vendor claims reductions of 20 to 30 percent in required stock, 2 to 5 percent more realised margin and 10 to 20 percent more realised sales; these are the vendor's own figures, published without a methodology.
What it does
- Forecast demand at SKU level, down to variant, colour and size
- Build collaborative pre-season budgets with version control, open-to-buy and intake planning
- Plan collections and generate first orders and reorders, with pack optimization
- Automate allocation, replenishment, inter-store transfers and consolidation
- Plan stock across physical stores and online channels together
- Optimize logistics through load estimation, load balancing and route planning
- Steer end-of-season markdown budgets and analyse promotions
When to use Thunderstock / When not to
A quick filter to help you decide if Thunderstock is the right fit.
When to use Thunderstock
- Fashion merchandisers and planners who still run a whole season out of spreadsheets
- Buyers assembling collections and reorders across thousands of variants, colours and sizes
- Multi-store, multi-channel retailers whose demand differs by country, city and channel
- Stock controllers handling allocation, replenishment and inter-store transfers by hand
- Non-food retail chains beyond apparel, such as footwear, furniture or home appliances
When not to use Thunderstock
- Teams that want to sign up, test and compare prices without ever speaking to a salesperson
- Developers looking for a product API or public technical documentation
- Anyone who needs a mobile app: the platform runs in the browser and nowhere else
- Buyers whose procurement process requires published terms, a privacy policy or a DPA up front
- Businesses outside retail merchandising, since every engine is built around stock and collections
How to use Thunderstock
A typical end-to-end flow, from setup to results.
- Size the opportunity first with the public ROI calculator on the Cases page
- Choose a demo format on the contact page: a 15-minute introduction, a 60-minute product demo or a 90-minute deep dive
- Book the slot through the scheduling link, or send the contact form if you prefer to write first
- Discuss scope and commercial terms with the vendor, since no rate card is published
- Connect your retail data with the vendor's integration team, working alongside your own data people
- Start with a single engine, typically stock optimization, and refine it before going further
- Roll out the remaining engines step by step rather than all at once
- Log in to the browser application for day-to-day work; there is nothing to install
- Review and approve the system's proposals, such as transfers and reorders, instead of letting them run unattended
- Use the authenticated documentation site for release notes and training material
Pros & Cons
Pros
- Covers the whole merchandising cycle in one platform, from pre-season budget to end-of-season markdown, instead of four or five separate tools
- Forecasting granularity goes down to the individual variant, colour and size in a given store
- Budgets are genuinely collaborative, with version control and a merge into one master version
- The vendor commits to explainable logic rather than a black box, and keeps a human approval step on its proposals
- European vendor with a named, publicly listed team and a real head office in the Netherlands
- Structured product documentation with a regularly updated, publicly listed release-note history
- Free demos in three lengths and a public ROI calculator, so the opportunity can be sized before any commitment
Cons
- No pricing is published anywhere: no rate card, no range, not even an order of magnitude
- No product API and no API documentation of any kind
- The product documentation exists but sits entirely behind a login
- No self-service trial, so the only way in is a sales demo
- No list of integrations is published, although the platform has to connect to the retailer's systems
- No terms of service, no usable privacy policy and no data processing agreement
- Browser only and strongly vertical: no mobile app, and little relevance outside fashion and non-food retail
Pricing & Plans
Thunderstock publishes no prices. The site has no pricing page, the /pricing path returns a genuine 404 and the sitemap confirms that no such page exists; none of the pages collected carries a rate, a range or an order of magnitude. The platform is therefore sold on quotation, after a sales conversation. What is offered free of charge is the demonstration, in three lengths: a 15-minute introduction, a 60-minute product demo and a 90-minute deep dive. These are guided sessions rather than a trial of the software, and no permanent free plan and no free trial are mentioned anywhere on the site.
Data, GDPR & hosting
A consolidated view of how Thunderstock handles your data.
GDPR overview
Thunderstock BV is established in the Netherlands and therefore operates inside the European Union, yet the site publishes no GDPR material at all. Across the ten pages collected on 4 September 2026 there is not one mention of the GDPR or of its Dutch name, the AVG. The only legal URL that exists, the privacy policy page, answers normally but its body is an unedited Webflow template: placeholder Latin text and demonstration labels such as Block quote and Item 1. No data protection officer is named, no privacy contact address is given and no data processing agreement is offered. The site also loads Google Tag Manager without a cookie banner or any consent management platform. Nothing published here allows the vendor's compliance to be assessed in either direction, so these documents have to be requested directly before any contract.
Hosting summary
The vendor publishes nothing about data hosting. There is no trust centre, no security page and no working privacy policy, so no jurisdiction, no hosting country, no region and no subprocessor is declared anywhere on the site. The only observation available is a network measurement rather than a vendor statement: the thunderstock.nl domain resolves to an Amazon Web Services address in Frankfurt, Germany. That address serves the redirection to the main site and says nothing reliable about where customer data actually lives, so it should not be read as a hosting commitment. The marketing site itself is served by a website builder through a content delivery network, while the application runs on a separate subdomain. Anyone evaluating Thunderstock for a retailer's commercial data should treat hosting location, data residency and subprocessor disclosure as open questions and obtain written answers from the vendor before signing.
Things to keep in mind
Risks and trade-offs to weigh before adopting Thunderstock.
- There is no usable privacy policy: the page that should carry one returns an unedited website template with placeholder text and demonstration labels, so how personal data is handled is simply unstated.
- No terms of service, legal notice, cookie policy or data processing agreement exist either, an absence confirmed by the site's own fifteen-URL sitemap rather than merely assumed.
- Google Tag Manager is loaded with no cookie banner and no consent management platform, from a vendor established in the European Union.
- Nothing is published about where customer data is hosted, which subprocessors are involved, how long data is kept, or whether it feeds model training.
- The impact figures on the Cases page, twenty to thirty percent less stock and up to five percent more margin, are vendor claims with no published methodology or independent audit.
- Handing allocation and replenishment to an automated engine can slowly erode a team's own feel for demand; the vendor's own customer story frames trust and change management as the hard part, which is an argument for keeping real human review on the proposals rather than rubber-stamping them.
- Small signs of unfinished fine print, such as a street number that differs between the contact page metadata and the footer, are worth noting when the same site also carries no legal documents.
Setup & Integrations
Technical difficulty
Moderate, and mostly organisational rather than technical. Nothing is installed: the platform runs in a browser. The real work is connecting the retailer's data, which the vendor supports with a dedicated integration lead working alongside the customer's own data team. The published customer story describes a staged rollout, one engine implemented, tested and refined before the next, and the vendor claims implementation without disruption, heavy IT burden or long rollout cycles. Expect the harder part to be adoption: teams have to learn to trust and act on the system's recommendations.
Deployment
Supported languages
Behind Thunderstock
Social
Resources
All the official URLs gathered for verification and reference.
Frequently asked questions
What does Thunderstock actually do?
Which modules make up the platform?
Who is it built for?
How much does it cost?
Is there a free trial or a free plan?
Does Thunderstock offer an API?
How do you access the platform, and is there a mobile app?
Is there product documentation?
Who publishes the tool, and where is it based?
Does the site publish a privacy policy or terms of service?
Should you pick Thunderstock?
Thunderstock is a serious, narrowly aimed product. Very few tools try to hold the whole merchandising cycle together, and fewer still do it at the granularity this one claims: variant, colour and size, store by store. The five engines map cleanly onto how a fashion planning department actually works, the budget module solves a real collaboration problem with version control and merging, and the vendor's insistence on explainable recommendations with a human approval step is the right instinct for a domain where trust is the adoption bottleneck. The named team, the Dutch head office and the steady stream of release notes all point to a going concern rather than a demo.
The difficulty is everything that surrounds the software. There is no published price, no range and no way to self-serve, so the first real information about cost arrives in a sales meeting. The documentation is complete but locked behind a login, which means a buyer cannot judge depth before committing. Most seriously, the vendor publishes no terms of service and no working privacy policy: the page that should carry one returns an unedited template, and there is no data processing agreement, no cookie policy and no statement about hosting, retention or model training. For a European vendor handling a retailer's commercial data, that is a gap a procurement team will have to close in writing.
The right approach is to take the free demo, ask for the missing legal documents and a written quotation in the same breath, and judge the platform on both answers. The functional case looks strong; the paperwork, as published today, does not yet exist.
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