Migrate from TinyMCE or CKEditor to RichTextBox

Why teams move

• Perpetual license. No subscription, no per-load metering, no AI usage-credit invoices.
• One SKU for everything. Track Changes, Comments, Revision History, Mentions, AI — all in the base license. TinyMCE premium billing covers these separately.
• Self-host at the entry tier. TinyMCE gates self-hosting to Enterprise; we self-host from day one.
• Native ASP.NET Core Tag Helper — <richtextbox> as a first-class Razor citizen, not a JS wrapper.

Step-by-step checklist

1. Install the NuGet: dotnet add package RichTextBox.AspNetCore --version 1.0.0-preview.12
2. Register in Program.cs: builder.Services.AddRichTextBox(); · app.MapRichTextBoxUploads();
3. Drop your RichTextBox.lic file next to Program.cs (contact sales for a trial key — the demo resolver runs key-less).
4. Replace <textarea id="..."> + TinyMCE init script with a single <richtextbox asp-for="Body" toolbar="full" /> tag.
5. Map your TinyMCE plugins: and toolbar: config to our toolbar attribute — see the cheat sheet below.
6. Wire an AI resolver if you use TinyMCE AI: builder.Services.AddRichTextBoxOpenAiResolver(opts => opts.ApiKey = ...). No proxy server needed.
7. Replace any custom content filters with config.filterhtml / filterbeforepaste callbacks.
8. Existing HTML content keeps working; submit your forms as normal, the posted value is the editor's HTML.

Config cheat sheet

Basic setup

tinymce.init({
  selector: '#editor',
  plugins: 'lists link image table code',
  toolbar: 'bold italic | bullist numlist | link image',
  height: 500
});

<richtextbox
    asp-for="Body"
    toolbar="custom"
    height="500px" />

@* Define "custom" toolbar once at site level *@
<script>
RTE_DefaultConfig.toolbar_custom =
  "{bold,italic}|{insertunorderedlist,insertorderedlist}|{insertlink,insertimage}";
</script>

AI (TinyMCE AI → RichTextBox AI Toolkit)

tinymce.init({
  plugins: 'ai',
  toolbar: 'ai',
  ai_request: (request, respondWith) => {
    respondWith.stream((streamMessage) =>
      fetch('/my-proxy-to-openai', {
        method: 'POST',
        body: JSON.stringify({ ... })
      }).then(/* ... */)
    );
  }
});

builder.Services.AddRichTextBox();
builder.Services.AddRichTextBoxOpenAiResolver(opts =>
{
    opts.ApiKey = builder.Configuration["OpenAI:ApiKey"];
    opts.Model  = "gpt-4o-mini";
});

@* Page *@
<richtextbox asp-for="Body"
             enable-ai-toolkit="true" />

Track Changes, Comments, Revision History

Three separate TinyMCE premium add-ons → three base-license attributes.

tinymce.init({
  plugins: 'tinycomments a11ychecker '
         + 'revisionhistory',
  tinycomments_mode: 'embedded',
  tinycomments_author: 'current user',
  // Track Changes requires separate license
});

<richtextbox asp-for="Body"
    enable-tracked-changes="true"
    enable-comments="true"
    enable-revision-history="true"
    current-user-id="@User.Id"
    current-user-name="@User.Name" />

Plugin equivalence

Behavior differences to know about

What you gain

• Dictation (mic button, Web Speech API) — TinyMCE doesn’t ship this.
• Slash commands (Notion-style / inline picker) — more mature than TinyMCE's autocompleter API.
• Shared review ledger — AI suggestions + human track-changes + comments in one drawer. TinyMCE keeps these siloed.
• Blazor Server support, ASP.NET Web Forms, Classic ASP, PHP bindings.