WPT
wpt / css / css-variables / variable-substitution-basic.html
Spec: CSS Variables ↗
Runs: Chrome 155.0.8038.0 (wpt@b1a7025f8, 2026-09-02) | Firefox 157.0a1 (wpt@b1a7025f8, 2026-09-02) | Safari 251 preview (wpt@5ce815a83, 2026-08-27) | Ladybird 1.0-a7884 (wpt@b1a7025f8, 2026-09-02) | Servo Servo 0.5 (wpt@2ccd2cbf8, 2026-09-01) | Blitz 7727414ca (wpt@a95401e4e, 2026-09-02)
View on the Blitz WPT dashboard | Open test on wpt.live | wpt.fyi
| Chrome | Firefox | Safari | Ladybird | Servo | Blitz | |
|---|---|---|---|---|---|---|
| Total | 13/13 | 13/13 | 13/13 | 13/13 | 13/13 | 13/13 |
| Subtest | Chrome | Firefox | Safari | Ladybird | Servo | Blitz |
|---|---|---|---|---|---|---|
| Simple substitution test | PASS | PASS | PASS | PASS | PASS | PASS |
| You can't build up a single token where part of it is provided by a variable | PASS | PASS | PASS | PASS | PASS | PASS |
| You can't build up a single token where part of it is provided by a variable (percentages) | PASS | PASS | PASS | PASS | PASS | PASS |
| Multiple variable references in a single property | PASS | PASS | PASS | PASS | PASS | PASS |
| Multiple variable references in a single property (no spaces) | PASS | PASS | PASS | PASS | PASS | PASS |
| Fallback value | PASS | PASS | PASS | PASS | PASS | PASS |
| Fallback value which is also a variable reference | PASS | PASS | PASS | PASS | PASS | PASS |
| Multiple var references in fallback value | PASS | PASS | PASS | PASS | PASS | PASS |
| Multiple nested fallbacks | PASS | PASS | PASS | PASS | PASS | PASS |
| Bad variable reference that should inherit by default | PASS | PASS | PASS | PASS | PASS | PASS |
| Test that var reference doesn’t overwrite !important | PASS | PASS | PASS | PASS | — | — |
| Test that !important on a property that has a variable reference can overwrite !important | PASS | PASS | PASS | PASS | PASS | PASS |
| Test that !important inside of var reference can't overwrite !important on property | PASS | PASS | PASS | PASS | PASS | PASS |
| Test that var reference doesn’t overwrite !important | — | — | — | — | PASS | PASS |