itch.io

HTML5 uploads can fail for boring ZIP reasons: index.html nested in an extra folder, case-sensitive asset paths, absolute URLs, or archive entries written with backslashes.

I built BuildHarbor as a small offline checker for itch.io creators. It reads the ZIP structure locally, flags root entry and asset-path issues, can apply conservative repairs, and exports TXT/JSON reports plus a repaired ZIP.

Version 1.1.0 now inspects raw central-directory filename bytes before library normalization, so it can detect and normalize backslash separators without changing the original archive.

Project and screenshots: https://p4odebatata.itch.io/buildharbor-html5-zip-repair

If you publish HTML5 builds, which ZIP or asset-path failure has caused you the most trouble?

I built a small offline utility for developers who publish HTML5 games on itch.io.

BuildHarbor checks a ZIP for a missing root index.html, extra wrapping folders, case-sensitive asset paths, insecure external HTTP resources, and raw ZIP entry names that use backslashes. It can export TXT/JSON reports and a repaired copy while keeping the original archive untouched.

I would appreciate specific feedback on the project page:

1. Is the problem clear within five seconds?

2. Do the screenshots communicate the workflow?

3. Does the one-time price of $2.99 feel believable for this utility?

4. What information would stop you from trying it?

Project page: https://p4odebatata.itch.io/buildharbor-html5-zip-repair

Please be direct. I will use the feedback to improve both the page and the tool.

Your tests point to an itch.io mobile fullscreen/viewport issue rather than a ZIP packaging issue. I would keep the direct html.itch.zone workaround and report it against #881.

One quick way to rule out a second, independent failure is to inspect the archive itself: index.html at the ZIP root, relative and case-sensitive asset paths, no backslash entry names, and no external HTTP resources. I made a small offline checker for those preflight checks: https://p4odebatata.itch.io/buildharbor-html5-zip-repair

It will not fix the viewport bug, but it can confirm that the ZIP is clean before you spend time on runtime changes.

Thanks a lot — you found a real gap. I reproduced both cases and read the filename bytes in the ZIP central directory directly.

BuildHarbor 1.1.0 now:

• checks central-directory filename bytes before library normalization;

• reports the affected entries containing backslashes;

• offers an explicit “Normalize ZIP entry separators to /” repair;

• exports a new ZIP whose entry names use /, while preserving the original archive untouched;

• reopens and rescans the output to verify that no backslash entries remain.

I verified this with synthetic ZIPs. I still do not claim that every itch.io HTML5 runtime fails on backslash names; the final draft upload remains the authority. Capitalization and wrapping-folder checks remain in place too.

Thanks for pointing this out — your comment led directly to the fix: https://p4odebatata.itch.io/buildharbor-html5-zip-repair

Hi! I made BuildHarbor for HTML5 developers preparing an itch.io upload.

It checks your game ZIP for common packaging issues, including a missing root index.html, an extra wrapping folder, and supported asset-path capitalization mismatches.

You can review the findings, choose available repairs, and export a new ZIP without changing your original file. TXT and JSON reports are included.

It runs locally in a desktop browser: your game files aren't uploaded to a checking service.

This is a static checker, not a runtime debugger. You still need to test your final build on itch.io.

Introductory price: $2.99. Includes the app, a built-in worked example, and a Quick Start PDF.

Screenshots and full details:

https://p4odebatata.itch.io/buildharbor-html5-zip-repair

Happy to answer questions about the checks and their limitations.