unclecode/crawl4ai · error · ValueError

Unsupported chunking strategy

Error message

Unsupported chunking strategy

What it means

Error "Unsupported chunking strategy" thrown in unclecode/crawl4ai.

Source

Thrown at crawl4ai/legacy/web_crawler.py:140

        self,
        url: str,
        word_count_threshold=MIN_WORD_THRESHOLD,
        extraction_strategy: ExtractionStrategy = None,
        chunking_strategy: ChunkingStrategy = RegexChunking(),
        bypass_cache: bool = False,
        css_selector: str = None,
        screenshot: bool = False,
        user_agent: str = None,
        verbose=True,
        **kwargs,
    ) -> CrawlResult:
        try:
            extraction_strategy = extraction_strategy or NoExtractionStrategy()
            extraction_strategy.verbose = verbose
            if not isinstance(extraction_strategy, ExtractionStrategy):
                raise ValueError("Unsupported extraction strategy")
            if not isinstance(chunking_strategy, ChunkingStrategy):
                raise ValueError("Unsupported chunking strategy")

            word_count_threshold = max(word_count_threshold, MIN_WORD_THRESHOLD)

            cached = None
            screenshot_data = None
            extracted_content = None
            if not bypass_cache and not self.always_by_pass_cache:
                cached = get_cached_url(url)

            if kwargs.get("warmup", True) and not self.ready:
                return None

            if cached:
                html = sanitize_input_encode(cached[1])
                extracted_content = sanitize_input_encode(cached[4])
                if screenshot:
                    screenshot_data = cached[9]
                    if not screenshot_data:

View on GitHub (pinned to 7e80152142)

Solutions

1. Use a supported chunking strategy such as RegexChunking or SlidingWindowChunking.
2. Pass a ChunkingStrategy instance to the crawler call.

Example fix

crawler.run(url, chunking_strategy=RegexChunking())

When it happens

Trigger: Thrown at crawl4ai/legacy/web_crawler.py:140 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of unclecode/crawl4ai@7e80152142 (2026-08-14). Data as JSON: /api/errors/d062957d039230d7. Report an issue: GitHub.