BlazorFiddle - Blazor .Net Developer Playground and Code Editor in the Browser
BlazorFiddle is my online Blazor .NET developer playground at blazorfiddle.com — a place where you can edit code, run it, and share a link to a working example. https://blazorfiddle.com/ BlazorFiddle lets you work with more than a single snippet: you can run a project-like setup (multiple components), edit HTML (including your own CSS), and tweak program startup code for service registration—then share it as a runnable repro or demo link. Quick snapshot (as of Jan 3, 2026): Website: https://blazorfiddle.com/ It’s been publicly referenced 17 May 2019 in the Blazor community (e.g., early Reddit introduction; community tooling lists). Reddit It was upgraded over time (the app itself notes a migration “from Blazor 0.7 to .NET 6.0”). Visibility, reach, and ecosystem footprint BlazorFiddle became one of those tools people casually drop into conversations because it solves a simple pain: “show me the problem” (or “show me the idea”)—in a link. A few public, easy-to-verify places where BlazorFiddle shows up (just few examples): ASP.NET Core / Blazor issue tracker: people asked “is there an online live editor for Blazor?” and the answer was essentially “I’m only aware of blazorfiddle.com,” pointing directly to my site. GitHub Official .NET/Blazor bug repros: BlazorFiddle links were used to demonstrate issues in the ASP.NET Core repo. GitHub Stack Overflow answers: BlazorFiddle is frequently used as a live repro/demo in answers across years. Stack Overflow It was used hundreeds of times. Community tooling lists: it’s listed under “Tooling” in awesome-blazor . GitHub Community launch post: I introduced it publicly on Reddit as a Blazor playground and code editor. Reddit Broader dev chatter: it was even referenced in external tool discussions (e.g., StackBlitz issue thread). GitHub And for me personally: at its peak, BlazorFiddle reached thousands of users per day—people experimenting, creating fiddles, and sharing them in issues, chats, and Q&A threads. The story BlazorFiddle was born almost alongside MatBlazor . I was building a component library, constantly needing a way to prove a component works, share a runnable example, and give others a place to tweak parameters and immediately see results. That need shaped the whole product. The first version was intentionally minimal: essentially one component , no real app configuration, no CSS workflow—and the wild part was that it could compile and run the component directly in the browser . It felt unbelievably fast and “alive,” because the feedback loop was instant. Then Blazor changed dramatically as it evolved, and the original “compile in the browser” approach became harder to keep stable. I made the call to move compilation to the backend, even though it meant more complexity and (sometimes) a slower compile loop—because the payoff was huge: BlazorFiddle became more universal, able to handle richer scenarios. That’s when it turned into a real playground: edit multiple files/components (not just one), edit HTML and include custom CSS, edit Program.cs / startup to register services and write additional .NET code, and (crucially) compile in an isolated environment—in a dedicated Docker container—to keep the execution model safer. BlazorFiddle also became deeply connected to MatBlazor: MatBlazor’s own release notes mention the integration, and that integration is exactly what I originally wanted—click an example, open it in a runnable playground, tweak it, learn by doing. Today BlazorFiddle still works—and it still does the job it was built for: a simple, shareable, runnable Blazor sandbox. The app itself reflects the reality of its long lifespan (including the note that it was updated “from Blazor 0.7 to .NET 6.0,” and older saves may need upgrades). But like MatBlazor, it’s not a project I’m actively developing right now. Modern .NET + WASM has improved enough that “client-side compilation” could be revisited in a new way—and that idea is exciting—but I’m choosing not to restart that effort unless the right future context appears. What I do keep is the pride: BlazorFiddle became part of how the Blazor community shared knowledge—bugs, solutions, prototypes, and UI ideas—through a single link.
