Preserve the material before replacing the runtime
Adobe ended support for Flash Player in 2020. Old tutorials can still contain useful ideas, but a browser plug-in is no longer a sensible foundation for a new public website. Keep an archival copy of the original project and gather its images, audio, video, text and source files before changing anything.
List the behaviours the project actually needs. A video player, a slideshow and an interactive 3D scene require different replacements. “Convert Flash” is too broad a specification to estimate or test.
Choose the smallest suitable web technology
Ordinary audio and video should begin with native HTML media elements. A diagram may fit SVG. A drawing surface or custom visualisation may need Canvas. Keep forms, navigation and text in semantic HTML where possible rather than painting the entire interface into an image-like surface.
Our retained tutorials cover video migration and slideshow migration. They explain the modern workflow while preserving the old entry addresses.
Rebuild behaviour deliberately
Do not translate code line by line before understanding the original interaction. Identify the states, inputs and outputs. For a player, that includes loading, playing, paused, ended and failed states. For a slideshow, it includes manual navigation, focus and what happens when an image is missing.
Make those behaviours work with a keyboard and on a small screen. Add motion only after the basic task is usable. Respect reduced-motion preferences and provide a way to stop automatic movement.
Check rights and missing dependencies
Recovering an old media file does not automatically establish permission to republish it. Check licences for images, fonts, sound and bundled libraries. Replace unavailable external services with a documented current source or remove the dependency.
If an old demo relied on a remote API, confirm that the service still exists and that its current access rules allow your use. A working local animation can still fail when its data source is gone.
Test the replacement as a new application
Create a short acceptance checklist from the original purpose: the content loads, the essential interaction works, failures are understandable, and the experience is usable on phones and with a keyboard. Compare against that checklist, not just a screenshot of the old demo.
Where the original project has historical value, keep its files offline as an archive. The public replacement should explain the current approach without encouraging visitors to reinstall an unsupported browser plug-in.