Frequently Asked Questions

Browse our catalog, select a book, and click "Buy Now" or add it to your cart. Complete checkout with your email and payment details. You will receive a download link immediately after payment.

We accept major credit and debit cards (Visa, Mastercard, American Express) through Stripe, as well as PayPal. Depending on your device and browser, Stripe may also offer Apple Pay or Google Pay. Choose your preferred method at checkout.

No! All our products are digital eBooks delivered instantly via download link. There is no physical shipping involved, so you never pay shipping fees.

All prices are displayed in EUR (Euros). Your bank or card provider will automatically convert the amount to your local currency at their current exchange rate.

Yes. All prices shown include VAT where it applies, so the price you see is the price you pay. For EU customers, VAT is calculated at the rate of your country for e-books and shown on your invoice. No EU VAT is charged to customers outside the EU, but the displayed price stays the same.

Yes. An invoice is issued and emailed to you automatically after every purchase. It includes all details needed for business expense claims. If you need a copy resent or a correction, contact us with your order email.

Yes. During checkout you can enter your company name and EU VAT number, and the invoice will be issued to your company. For larger team purchases, contact us about volume pricing.

Yes! Contact us at info@dargslan.com for team licenses and volume discounts. We offer special pricing for companies, educational institutions, and training organizations.

Yes. Card payments are processed by Stripe, a PCI-DSS Level 1 certified payment processor, and PayPal payments are handled by PayPal. We never see or store your full card details. All connections are encrypted with TLS.

Check that your card details are correct and has sufficient funds. Try a different card or payment method. If the issue persists, contact your bank as they may be blocking the transaction.

First, check your spam/junk folder. If it is not there, contact us with your order email and we will resend your download link. We typically respond within 24 hours on business days.

Yes. New customers get 20% off their first order with the code NEWUSER20. If you registered through our new-user offer, the discount is applied automatically at checkout.

After purchase you receive an order confirmation email with your order number and download link. If you have an account, your orders are also listed under Order History in your account.

Yes. Most books have a free sample. Look for the "Read Free Sample" or "Download Sample" button on the book's product page.

After purchase you will receive an email with a secure download link. It opens your download page, where you can download every format included with the book (PDF, EPUB and, where available, the source code ZIP). If you have an account, the same downloads are in My Library.

Download links are valid for 7 days after purchase and allow 5 downloads per purchased book (each file you download counts as one). If your link has expired, contact us and we will reactivate it.

Yes. In My Library you can request a free extension, which our team reviews (usually within 24 hours), or buy 5 extra downloads instantly for €3.99.

Contact us with your order email or order number and we will reactivate your download link.

Yes! Once downloaded, the files are yours to keep. You can copy them to any of your personal devices - computer, tablet, phone, e-reader. There is no DRM restriction.

If you have an account, log in and open My Library to see all your purchases and download them while your link is active and within the download limit. Since the files are DRM-free, we recommend keeping a copy on your own devices.

Only to download the files initially. Once downloaded, the PDF and EPUB files are stored on your device and can be read completely offline.

Our eBooks come in PDF and EPUB. Most technical books also include the source code examples as a ZIP archive. The formats included with each book are shown on its product page.

PDF maintains fixed formatting and is best for technical books with code/diagrams. EPUB is reflowable text that adapts to screen size, better for pure reading on e-readers and phones.

Yes! EPUB files can be converted to Kindle format using free tools like Calibre. Alternatively, you can email the PDF directly to your Kindle (check Amazon's Send to Kindle feature).

Absolutely! Use Apple Books (built-in) for EPUB files, or any PDF reader for PDFs. Simply download the file and open it with your preferred reading app.

Yes! Use Google Play Books, Moon+ Reader, or any PDF/EPUB reader app from the Play Store. Download the file and open it with your preferred app.

For EPUB: Apple Books (iOS/Mac), Google Play Books (Android), Calibre (desktop). For PDF: Adobe Acrobat Reader, Foxit Reader, or any built-in PDF viewer.

No, we do not use DRM. Once purchased, the files are yours without restrictions. We trust our customers and believe DRM-free provides a better reading experience.

Where a book offers a source code download, it is a ZIP archive with the code examples used in the book. Whether a book includes source code is shown on its product page.

No account is required for one-time purchases. However, creating a free account gives you access to your order history, download library, wishlists, and faster checkout.

Click "Sign In" in the header, then "Create Account". Enter your email address and choose a password. Creating an account is free.

Click "Sign In", then "Forgot Password". Enter your email address and we will send you a password reset link valid for 1 hour. Check your spam folder if you don't see it.

You can update your name and phone number in your Profile settings. To change the email address of your account, contact us from your current email address and we will update it for you.

You can delete your account yourself under Account > Delete Account, or submit a request on our Data Protection page. We delete your personal data within 30 days as required by GDPR. Invoices must be retained for legal reasons.

Accounts are for individual use only. For team access, contact us about team licenses. Sharing accounts violates our Terms of Service and may result in account suspension.

The wishlist lets you save books you want to buy later. Click the heart icon on any book to add it. Access your wishlist from the header icon. Great for tracking books during sales!

Enter your coupon code in the cart or checkout page in the "Coupon code" field and click "Apply". Valid discounts will be applied to your order total immediately.

Only one coupon code can be used per order. Choose the one that gives you the best discount. Coupons cannot be combined with each other.

Check: Is the code typed correctly? Has it expired? Does it meet minimum order requirements? Is it valid for the items in your cart? Contact support if you believe there's an error.

Gift cards are currently issued on request. Contact us with the amount, the recipient's name and email and an optional message, and we will send you the details for payment.

Enter your 16-character gift card code at checkout in the Gift Card field. The balance will be applied to your order. Any remaining balance stays on the card for future use.

Yes. Open the Gift Cards page, choose Check Balance, and enter your gift card code to see the remaining balance and validity.

Yes! You can use both a gift card AND a coupon code on the same order. The coupon discount is applied first, then the gift card balance.

Bundles are curated collections of related books built around a topic or learning path, sold together for less than the books cost separately. Each bundle page shows the books included and the bundle price.

Create your own bundle! Add 2+ books for automatic discounts: 2 books = 10% off, 3 books = 15% off, 4 books = 20% off, 5+ books = 25% off. Access it from Bundle Builder in the menu.

Visit our Free Books page and enter your email address. After you confirm your newsletter subscription via the email we send you, you get an instant download link. Each free book can be downloaded once per email address.

We run seasonal sales (Black Friday, Christmas, New Year) and occasional flash sales. Subscribe to our newsletter to be notified first and get exclusive discount codes.

On a book's page you can ask to be notified when its price drops. We email you once when the price decreases. You can remove an alert on the book page at any time.

If you are signed in and leave items in your cart, we may send you reminder emails. Some reminders include a discount code.

Registered customers earn points on purchases and some other activities, and can redeem them for discount coupons. You earn 1 point per euro spent, and lifetime points unlock tiers with bonus points on everything you earn: Bronze (200+, +5%), Silver (500+, +8%) and Gold (1,000+, +12%). See your Loyalty page in your account and our Loyalty Program Terms for details.

Share your unique referral link from your account. When a friend makes their first purchase through your link, you receive a 15% discount coupon for your next order. Your friend can use our new-customer offer (20% off the first order with NEWUSER20). Find your link on the Refer a Friend page.

Yes! Content creators, bloggers, and educators can earn 30% commission on every eBook sale they refer. It is free to join, with a 30-day tracking cookie, a real-time dashboard, and monthly payouts via PayPal, Wise, or bank transfer. Apply at our Affiliate Program page, linked in the footer.

The Referral Program is for customers: share your link with friends and earn discount coupons. The Affiliate Program is for publishers and creators: earn a 30% cash commission on every sale you generate, paid out monthly. Affiliates get a dedicated dashboard with click and conversion statistics.

Affiliate commissions are reviewed and paid out monthly once your approved balance reaches €25. Payouts are available via PayPal, Wise, or SEPA bank transfer - you can set your preferred method in your affiliate dashboard.

Click the "Unsubscribe" link at the bottom of any newsletter email. You'll be immediately removed from our mailing list. Note: This doesn't affect transactional emails (order confirmations, download links).

Yes! Students get 25% off any eBook, bundle, or series. Visit our Student Discount page (/students), enter your academic email (.edu, .ac.uk, .ac.jp, etc.), and verify it. You'll receive a unique one-time coupon code valid for 6 months.

We accept emails from accredited educational institutions worldwide, including .edu (US), .ac.uk (UK), .ac.jp (Japan), .edu.au (Australia), .ac.at (Austria), .edu.pl (Poland), and many more. If your institution uses a different domain, contact us and we'll review it.

The student discount program allows one code per email address. Each code is single-use and valid for 6 months. For additional savings, check our public coupons page or subscribe to our newsletter for exclusive deals.

Use the search bar at the top of the page. Our intelligent search understands synonyms and related terms. You can search by title, author, topic, or keywords. Results are ranked by relevance.

Browse our 3-level category hierarchy in the left sidebar. Categories are organized from broad topics to specific specializations. Click any category to see all books within it.

As you browse, we remember which books you have looked at during your visit so you can quickly return to them. This list is kept in your browser session and on your device and is not used for advertising.

After purchasing a book, go to that book's page and scroll to the Reviews section. Click "Write a Review", select your star rating (1-5), and write your review. Reviews are moderated before appearing publicly.

Yes! Customer reviews and ratings are displayed on each book's product page. We show the average rating and individual reviews to help you make informed purchasing decisions.

Tags are keywords that describe a book's content (e.g., "Python", "Machine Learning", "Beginner"). Click any tag to see all books with that tag. Tags help you discover related content.

Based on your cart items and browsing history, we suggest related books you might enjoy. These cross-sell recommendations help you discover complementary content in your areas of interest.

Our exit-intent popup offers exclusive deals to first-time visitors! If you were about to leave, we might offer you a special discount code. Subscribe to our newsletter through the popup to receive the offer.

Featured: Hand-picked recommendations by our team. Bestseller: Top-selling books based on sales data. New Release: Recently published books. Sale: Books currently discounted from their regular price.

Reading Lists are expert-curated collections of books organized around a learning path or theme (e.g., "From Zero to DevOps Engineer"). Each list includes a description and recommended reading order. Visit the Reading Lists page to explore them.

Our IT Glossary is a free reference containing hundreds of technical terms with clear definitions, explanations, and links to related books. Great for beginners learning new terminology. Terms are also auto-linked in our blog articles for easy access.

Book Series group related books that are meant to be read in sequence (e.g., "Linux Mastery" series from beginner to advanced). Visit the Series page to see all available series with their books in recommended order.

Yes. Click "Compare" on up to 3 books, then open the comparison to see price, page count, rating, formats and category side by side.

Our "Books by Role" section curates the best books for specific career paths - Beginners, System Administrators, DevOps Engineers, Web Developers, and more. Visit Books by Role in the footer to find books matched to your professional goals.

Try: 1) Different browser (Chrome, Firefox, Edge), 2) Disable download blockers/ad blockers, 3) Check your Downloads folder, 4) Try right-click > Save Link As. Contact support if still not working.

Re-download the file using your download link. If you've used all downloads, request a free extension. If the file is still corrupted, contact support with your order number.

Make sure you're viewing at 100% zoom. Some PDF readers default to lower quality for faster loading. Check your reader's quality/rendering settings.

Windows 10/11 can open ZIP files natively. For Mac, double-click the file. If issues persist, use free software like 7-Zip (Windows) or The Unarchiver (Mac).

Check any README or setup notes included in the ZIP and make sure you have the required software versions installed. If an example still does not work, contact us with the book title and the example, and we will help.

Thank you for helping us improve! Please contact us via the Contact page with the book title, page number and a description of the error. Corrections are included in updated files of the book.

Yes. When we significantly update a book you purchased (for example error corrections or a new edition), the updated files are made available in your account library at no additional charge.

Visit our Contact page or email info@dargslan.com. Include your order number for faster service. We respond within 24 hours during business days (Mon-Fri, 9AM-6PM CET).

We currently offer support via email and our contact form only. This allows us to provide detailed, documented responses. Most inquiries are resolved within 24 hours.

We do not offer a general voluntary money-back guarantee or change-of-mind refunds for downloaded eBooks. The digital-content withdrawal exception applies only when all legal requirements are met, including prior express consent, acknowledgment and the required confirmation, and supply begins with downloading. Rights concerning defective or non-conforming content and incorrect charges remain unaffected. See our Refund Policy or contact support to make a request.

Change-of-mind returns are not possible for downloaded eBooks when you gave the required consent and acknowledgment at checkout. Until you start downloading, you can withdraw within 14 days using our withdrawal form. If you received the wrong file or it is defective, contact us and we will fix it or refund you.

Each purchase is licensed for personal use only. Sharing, distributing, or reselling our eBooks is prohibited. For team access, please contact us about team licenses.

We comply fully with GDPR. We collect only necessary data, encrypt all transmissions, never sell your data, and use industry-standard security. See our Privacy Policy for full details.

We collect your email, name (if provided), order history and the payment data needed for invoicing. We do NOT store card numbers. Our own visitor statistics use pseudonymous identifiers; analytics and marketing cookies are only used with your consent. See our Privacy Policy.

Yes! Under GDPR Article 15, you can request a copy of all data we hold about you. Submit a request on our Data Protection page and we'll respond within 30 days.

Yes! Under GDPR Article 17, you have the right to erasure. Submit a request on our Data Protection page. Note: We must retain invoice data for 10 years per tax law.

Yes. Essential cookies for site function (cart, login) are always used. Analytics and marketing cookies require your consent. Manage preferences via Cookie Settings in the footer.

Dargslan s.r.o. is a Slovak company specializing in technical eBooks. Visit our About page and Impressum for full company details, registration numbers, and contact information.