# I Built the Same App with Fable 5, Opus 4.8, and Sonnet 5…The Results Weren’t Even Close

> Source: <https://pub.towardsai.net/i-built-the-same-app-with-fable-5-opus-4-8-and-sonnet-5-the-results-werent-even-close-61d316461e7f?source=rss----98111c9905da---4>
> Published: 2026-07-15 03:01:14+00:00

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# I Built the Same App with Fable 5, Opus 4.8, and Sonnet 5…The Results Weren’t Even Close

Anthropic now has three models that can code:

- Fable 5 at the top
- Opus 4.8 in the middle
- And Sonnet 5 as the new free default.

I built the same app on all three.

I used the same spec, the same stack, and the same judgment criteria. The prompt counts tell the whole story.

## My Spec

I used a real client spec.

An expense tracker with five features:

- Auth via email/password with protected routes
- Dashboard with total spending, category breakdown chart, and monthly trend line
- Add expense form with description, amount, category dropdown, and date picker
- Expenses table with category filter and CSV export
- Mobile responsive throughout

The spec(Remember to add your Supabase project URL and anon key):

```
Build a team expense tracker app.Stack: React, Vite, TypeScript, Tailwind CSS, Supabase.Supabase project URL and anon key are in .env as VITE_SUPABASE_URL and VITE_SUPABASE_ANON_KEY.The database…
```