Model lifecycle
Claude Fable 5
Released 2026-06-09 · Back to Claude
Exact-version signals observed 2026-08-07–2026-08-27 · n=469
Lifecycle updated daily · latest complete UTC day 2026-08-27
- Fixed 14-day baseline
- 57.5 n=196
- Latest 28 days
- 57.3 n=469
- Change vs baseline
- −0.2
- 90-day slope
- – pts / 30 days
14-day rolling experience
Each daily point summarizes the previous 14 complete UTC days. The dashed line is the fixed release baseline; the verdict still uses independent non-overlapping 14-day segments.
2 of 4 independent 14-day segments ready for trend judgment.
What explains the change
Experience change and discussion-mix change are separated. These are observational contributions, not proof of cause.
Largest negative experience contributions: Safety & refusals.
| Category | Baseline → current | Category change | Weight share | Experience contribution | Discussion-mix contribution |
|---|---|---|---|---|---|
| Safety & refusals | Baseline → current24.6 → 18.8n=24 → 49 | Category change−5.8 | Weight share13.0% → 11.3% | Experience contribution−0.71 | Discussion-mix contribution+0.62 |
| Coding | Baseline → current63.7 → 65.5n=23 → 64 | Category change+1.8 | Weight share12.7% → 14.5% | Experience contribution+0.24 | Discussion-mix contribution+0.13 |
| General text | Baseline → current46.7 → 48.0n=79 → 200 | Category change+1.3 | Weight share36.6% → 39.5% | Experience contribution+0.48 | Discussion-mix contribution−0.29 |
| Reasoning | Baseline → current80.5 → 83.7n=58 → 119 | Category change+3.2 | Weight share32.5% → 27.4% | Experience contribution+0.96 | Discussion-mix contribution−1.29 |
| Image / vision | Baseline → currentnot enough datan=0 → 0 | Category change– | Weight share– | Experience contribution– | Discussion-mix contribution– |
| Local deploy | Baseline → currentnot enough datan=0 → 0 | Category change– | Weight share– | Experience contribution– | Discussion-mix contribution– |
| Roleplay / creative | Baseline → currentnot enough datan=4 → 7 | Category change– | Weight share– | Experience contribution– | Discussion-mix contribution– |
| Speed & latency | Baseline → currentnot enough datan=8 → 30 | Category change– | Weight share– | Experience contribution– | Discussion-mix contribution– |
| Video generation | Baseline → currentnot enough datan=0 → 0 | Category change– | Weight share– | Experience contribution– | Discussion-mix contribution– |
Unresolved contribution from categories below the sample threshold: −0.36 pts.
Lifecycle scores use the same experience-signal weights as the main index, without sample shrinkage after n=30. They measure public user perception, not model capability or backend causes.