Block Poster Maker

Inspiration

Printing a large image at home should not require a large-format printer, expensive software, or a confusing chain of export and printer settings.

We built BlockPoster.ai to turn an ordinary photo, illustration, or AI-generated image into a wall-sized poster made from standard sheets of paper. The idea is simple: upload one image, choose a layout, preview every page, download a print-ready PDF, and assemble a larger result at home.

We also wanted the experience to work for people who arrive with different goals: making classroom maps, party decorations, photo walls, event signage, or original AI artwork. That is why the poster workspace lives directly on the homepage instead of behind a complicated editor.

What it does

BlockPoster.ai is a browser-based block poster maker that helps users print one large image across multiple pages. Users can:

• Upload JPG, PNG, WebP, or PDF files and choose a PDF page.
• Create an original image with AI, then turn it into a printable poster.
• Choose paper size, portrait or landscape orientation, page width, height, margins, overlap, crop, and Fit or Fill behavior.
• Preview the final poster grid and individual printable sheets before downloading.
• Download a PDF that includes an assembly guide, page labels, trimming guidance, and poster tiles.
• Print at Actual Size / 100%, trim overlapping edges, and assemble the sheets into one larger image.
• Save local projects in the browser and return to their layouts later.
• Use the product in ten languages, including English, French, German, Italian, Spanish, Portuguese, Russian, Chinese, Japanese, and Turkish.

The basic PDF workflow is free without an account: it supports up to five sheets across, up to 150 DPI, and includes a watermark. Paid options unlock watermark-free output, up to ten sheets across, and up to 300 DPI.

How I built it

BlockPoster.ai is built as a TypeScript web application with React and Vite on the frontend, plus an Express server with tRPC for type-safe client-server communication.

The core poster workflow runs in the browser wherever possible. Image upload, crop choices, page-grid calculation, print previews, and PDF layout are designed around a local-first experience so ordinary poster images do not need to be uploaded to a server just to be split and printed.

The app includes:

• React and TypeScript for the interactive poster studio.
• Vite for the frontend build workflow.
• Express and tRPC for backend APIs.
• Drizzle ORM and MySQL for durable product data such as accounts, purchases, support tickets, and administrative records.
• Stripe for subscriptions and one-time poster/AI-credit purchases.
• Google OAuth and Resend email verification for sign-in.
• AI image creation inside the same workspace.
• Private support tickets with encrypted text and screenshots, admin-only translation, and reply notifications.
• Server-rendered public pages with localized metadata, canonical URLs, reciprocal hreflang links, structured data, sitemap support, and multilingual tutorials.
• Automated checks with TypeScript and Vitest. ## Challenges I ran into The hardest challenge was making the result genuinely printable rather than merely showing a grid over an image.

A multi-page poster depends on paper size, printer margins, orientation, overlap, crop behavior, source-image resolution, page count, and PDF scaling. We had to make these choices visible before export, while also preventing users from accidentally printing a previously tiled PDF through another printer “Poster” mode.

Another challenge was balancing privacy with useful product features. Standard uploaded poster images stay local to the browser, while optional AI generation and user-initiated support screenshots have clearly separated server-side flows.

International SEO was also a meaningful challenge. Public content needs localized routes, correct canonical URLs, reciprocal hreflang tags, real server-rendered text, sitemap entries, and language-aware navigation without exposing private account or support content.

Accomplishments that I'm proud of

• Built a complete print workflow that turns one image into a practical, assembled multi-page poster.
• Kept the primary image-splitting experience local in the browser.
• Added a live layout preview, printable PDF pages, overlap guidance, page labels, and a calibration page.
• Combined local uploads, PDF import, optional AI image generation, and print settings in one homepage workspace.
• Created a free workflow that users can try without an account.
• Added ten-language support with localized public routes and international SEO.
• Built a private support system with visitor submission, encrypted attachments, admin-only translation, and unread reply indicators.
• Made payment upgrades preserve the user’s existing workspace instead of forcing them to rebuild a poster after checkout.
• Added a detailed tutorial page that explains how to print a large image on multiple pages and lets visitors use the full poster studio directly within the guide. ## What I learned This project reinforced that a good creator tool is not only about generating an output. It has to help users understand the physical result.

For BlockPoster.ai, that meant explaining the difference between a poster grid and printer scaling, showing how many sheets will be printed, including an assembly guide, and making it clear that the final PDF should be printed at Actual Size / 100%.

I also learned how much product architecture matters for privacy. Keeping ordinary poster uploads local while handling optional AI requests, accounts, payments, and support messages through narrowly scoped server flows created a clearer and safer experience.

Finally, multilingual SEO is much more than translating a headline. It requires localized body content, metadata, canonical URLs, hreflang relationships, route handling, and sitemap coverage that all stay consistent.

What's next for Block Poster Maker

Next, we want to improve the creation-to-print journey even further:

• Add more layout presets for classrooms, birthdays, photo walls, and events.
• Improve mobile print guidance for users whose printer dialogs hide scale settings.
• Add more AI creation styles designed specifically for large-format printing.
• Expand print-quality guidance based on source image resolution and final poster size.
• Continue improving multilingual tutorials and country-specific print guidance.
• Add more project-sharing and reusable layout capabilities.
• Keep making large-image printing accessible from an ordinary home printer.

Built With

• blockposter.ai-is-built-as-a-typescript-web-application-with-react-and-vite-on-the-frontend
• react
• typescript
• vite