Model comparison
Claude Haiku 4.5 vs Claude Mythos 5
Head-to-head evidence from 1 shared benchmark result across 1 category. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Claude Haiku 4.5 #77 (Estimated); Claude Mythos 5 #1 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude Haiku 4.5 and Claude Mythos 5 share 1 comparable benchmark result. 2 of 8 categories are comparable. 4 results are unique to Claude Haiku 4.5; 14 to Claude Mythos 5.
Updated July 23, 2026- Shared results
- 1
- Claude Haiku 4.5 only
- 4
- Claude Mythos 5 only
- 14
- Comparable categories
- 2 / 8
Pick Claude Mythos 5 if you want the stronger benchmark profile. Claude Haiku 4.5 only becomes the better choice if you want the cheaper token bill or you would rather avoid the extra latency and token burn of a reasoning model.
Confidence note. This is a partial-evidence comparison with 1 shared benchmark result across 1 evidence category; 2 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
Claude Mythos 5 is clearly ahead on the BenchAlign aggregate, 83.93 to 56.58. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Claude Mythos 5's sharpest advantage is in mathematics, where it averages 97.6 against 4.9. The single biggest benchmark swing on the page is SWE-bench Verified, 73.3% to 95.5%.
Claude Mythos 5 is also the more expensive model on tokens at $10.00 input / $50.00 output per 1M tokens, versus $1.00 input / $5.00 output per 1M tokens for Claude Haiku 4.5. That is roughly 10.0x on output cost alone. Claude Mythos 5 is the reasoning model in the pair, while Claude Haiku 4.5 is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. Claude Mythos 5 gives you the larger context window at 1M+, compared with 200K for Claude Haiku 4.5.
Category breakdown
Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.
| Category | Claude Haiku 4.5 | Δ | Claude Mythos 5 |
|---|---|---|---|
| Math | Claude Haiku 4.54.9 | Margin→ 92.7 | Claude Mythos 597.6 |
| Coding | Claude Haiku 4.573.3 | Margin→ 16.4 | Claude Mythos 589.7 |
| Agentic | Claude Haiku 4.5Not measured | MarginNo overlap | Claude Mythos 587.0 |
| Knowledge | Claude Haiku 4.5Not measured | MarginNo overlap | Claude Mythos 568.5 |
| Multimodal | Claude Haiku 4.5Not measured | MarginNo overlap | Claude Mythos 593.5 |
Decisive benchmark drivers
The largest measured benchmark gaps in this matchup, with exact reported values.
More
- Source ↗
SWE-bench Verified
CodingA 73.3%B 95.5%Winner: Claude Mythos 5Δ 22.2SWE-bench Verified: Claude Haiku 4.5 scored 73.3%; Claude Mythos 5 scored 95.5%. Claude Mythos 5 wins this benchmark.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Claude Haiku 4.5 | Claude Mythos 5 | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude Haiku 4.5$1 input / $5 output | Claude Mythos 5$10 input / $50 output | Claude Haiku 4.5 has the lower combined listed price. |
| Generation speedtokens per second | Claude Haiku 4.5Not available | Claude Mythos 5Not available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude Haiku 4.5Not available | Claude Mythos 5Not available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude Haiku 4.5200K | Claude Mythos 51M+ | Claude Mythos 5 lists the larger context window. |
Benchmark Deep Dive
Agentic5 benchmarks
CodingClaude Mythos 5 wins3 benchmarks
Knowledge3 benchmarks
MathClaude Mythos 5 wins3 benchmarks
Multilingual1 benchmarks
| Benchmark | Claude Haiku 4.5 | Claude Mythos 5 | Result |
|---|---|---|---|
| SWE MultilingualSource | — | 92.2% | Not comparable |
Frequently Asked Questions (3)
Which is better, Claude Haiku 4.5 or Claude Mythos 5?
Claude Mythos 5 is ahead on BenchLM's BenchAlign leaderboard, 83.93 to 56.58. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 73.3% and 95.5%.
Which is better for coding, Claude Haiku 4.5 or Claude Mythos 5?
Claude Mythos 5 has the edge for coding in this comparison, averaging 89.7 versus 73.3. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.
Which is better for math, Claude Haiku 4.5 or Claude Mythos 5?
Claude Mythos 5 has the edge for math in this comparison, averaging 97.6 versus 4.9. Claude Haiku 4.5 stays close enough that the answer can still flip depending on your workload.
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