Status
This page documents the implementation status of various HTML and CSS features in Blitz.
This page documents Blitz's scores on the "css" subsuite of the Web Platform Tests.
Note: As it does not have a JavaScript engine, Blitz can only run about 20% of the total subtests. In the numbers below, tests that Blitz can't run are ignored and percentages are relative to the number of tests run.
Data from commit:
1093b86 wpt: skip non-UTF-8 test files instead of crashing (#659) (2026-08-09)
wpt / css / compositing
| Area | Interop Score | Tests | Test % | Subtests | Subtest % |
|---|---|---|---|---|---|
| Total | 15.00% | (9/60) | 15.00% | (9/60) | 15.00% |
| background-blending | 50.00% | (1/2) | 50.00% | (1/2) | 50.00% |
| isolation | 0.00% | (0/1) | 0.00% | (0/1) | 0.00% |
| mix-blend-mode | 11.60% | (5/43) | 11.63% | (5/43) | 11.63% |
| svg | 50.00% | (1/2) | 50.00% | (1/2) | 50.00% |
| Test | Subtests | Subtest % | Status |
|---|---|---|---|
| root-element-background-contain-hidden-crash.html | (1/1) | 100.00% | PASS |
| root-element-background-image-opaque-crash.html | (1/1) | 100.00% | PASS |
| root-element-background-image-transparency-001.html | (0/1) | 0.00% | FAIL |
| root-element-background-image-transparency-002.html | (0/1) | 0.00% | FAIL |
| root-element-background-image-transparency-003.html | (0/1) | 0.00% | FAIL |
| root-element-background-image-transparency-004.html | (0/1) | 0.00% | FAIL |
| root-element-background-margin-opacity.html | (0/1) | 0.00% | FAIL |
| root-element-background-transparency.html | (0/1) | 0.00% | FAIL |
| root-element-blend-mode.html | (0/1) | 0.00% | FAIL |
| root-element-filter.html | (0/1) | 0.00% | FAIL |
| root-element-opacity-change.html | (0/1) | 0.00% | FAIL |
| root-element-opacity.html | (0/1) | 0.00% | FAIL |