grafana/k6 · error

unknown compression algorithm %s, supported algorithms are %

Error message

unknown compression algorithm %s, supported algorithms are %s

What it means

The 'compression' request option named an algorithm that httpext.CompressionTypeString doesn't recognize. Supported values are listed in the message (gzip, deflate, br/zstd...); the offending algorithm is echoed.

Source

Thrown at js/modules/k6/http/request.go:387

				if common.IsNullish(jarV) {
					continue
				}
				if v, ok := jarV.Export().(*CookieJar); ok {
					result.ActiveJar = v.Jar
				}
			case "compression":
				algosString := strings.TrimSpace(params.Get(k).ToString().String())
				if algosString == "" {
					continue
				}
				algos := strings.Split(algosString, ",")
				var err error
				result.Compressions = make([]httpext.CompressionType, len(algos))
				for index, algo := range algos {
					algo = strings.TrimSpace(algo)
					result.Compressions[index], err = httpext.CompressionTypeString(algo)
					if err != nil {
						return nil, fmt.Errorf("unknown compression algorithm %s, supported algorithms are %s",
							algo, httpext.CompressionTypeValues())
					}
				}
			case "redirects":
				result.Redirects = null.IntFrom(params.Get(k).ToInteger())
			case "tags":
				if err := common.ApplyCustomUserTags(rt, &result.TagsAndMeta, params.Get(k)); err != nil {
					return nil, fmt.Errorf("invalid HTTP request metric tags: %w", err)
				}
			case "auth":
				result.Auth = params.Get(k).String()
			case "timeout":
				t, err := types.GetDurationValue(params.Get(k).Export())
				if err != nil {
					return nil, fmt.Errorf("invalid timeout value: %w", err)
				}
				result.Timeout = t
			case "throw":

View on GitHub (pinned to 01ffac6f24)

Solutions

1. Use one of the supported algorithms from the message, e.g. compression: 'gzip'
2. Check for typos and stray whitespace in the algorithm name

When it happens

Trigger: Thrown at js/modules/k6/http/request.go:387 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of grafana/k6@01ffac6f24 (2026-08-18). Data as JSON: /api/errors/07adad9ecf512b0c. Report an issue: GitHub.