slidevjs/slidev · error · Error

[slidev] "prism" support has been dropped. Please use "highl

Error message

[slidev] "prism" support has been dropped. Please use "highlighter: shiki" instead

What it means

The Slidev config loader rejects highlighter: 'prism'. Prism support was removed; 'shiki' is the only supported highlighter ('shikiji' is auto-remapped to 'shiki' with a warning).

Source

Thrown at packages/parser/src/config.ts:111

      ...headmatter?.htmlAttrs,
    },
    themeConfig: {
      ...defaultConfig.themeConfig,
      ...themeMeta.defaults?.themeConfig,
      ...headmatter.config?.themeConfig,
      ...headmatter?.themeConfig,
    },
  }

  // @ts-expect-error compat
  if (config.highlighter === 'shikiji') {
    console.warn(`[slidev] "shikiji" is merged back to "shiki", you can safely change it "highlighter: shiki"`)
    config.highlighter = 'shiki'
  }

  // @ts-expect-error compat
  if (config.highlighter === 'prism')
    throw new Error(`[slidev] "prism" support has been dropped. Please use "highlighter: shiki" instead`)

  if (config.colorSchema !== 'dark' && config.colorSchema !== 'light')
    config.colorSchema = 'auto'
  if (themeColorSchema && config.colorSchema === 'auto')
    config.colorSchema = themeColorSchema

  config.aspectRatio = parseAspectRatio(config.aspectRatio)

  if (verify)
    verifyConfig(config, themeMeta)

  return config
}

export function verifyConfig(
  config: SlidevConfig,
  themeMeta: SlidevThemeMeta = {},
  warn = (v: string) => console.warn(`[slidev] ${v}`),

View on GitHub (pinned to 0d798ace58)

Solutions

1. Remove the highlighter: prism line to fall back to the default (shiki)
2. Explicitly set highlighter: shiki
3. Migrate any Prism-specific CSS/overrides to Shiki's CSS variables

Example fix

// before
---
highlighter: prism
---
// after
---
highlighter: shiki
---

if (config.highlighter && config.highlighter !== 'shiki' && config.highlighter !== 'shikiji') {
  throw new Error(`Unsupported highlighter: ${config.highlighter}. Use 'shiki'.`)
}

type Highlighter = 'shiki' | 'shikiji'
function isSupportedHighlighter(v: unknown): v is Highlighter {
  return v === 'shiki' || v === 'shikiji'
}

When it happens

Trigger: Setting highlighter: 'prism' in the slides.md headmatter or in headmatter themeConfig / slidev config.

Common situations: Old decks created on pre-0.48 Slidev; config snippets copied from outdated documentation; CI building a legacy deck against a new Slidev.

Related errors

• `loadTheme` is no longer supported.
• Invalid aspect ratio "${str}"
• [Slidev] ogImage: ${filename} not found
• [slidev] Failed to load "${PWA_PACKAGE}", which is required

AI-assisted analysis of slidevjs/slidev@0d798ace58 (2026-08-12). Data as JSON: /api/errors/3b6011ce8f8b608b. Report an issue: GitHub.