Zephyr FusionYC F25 landing page report.
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Zephyr Fusionhttps://www.zephyrfusion.com/

Your landing page’s weakest score is CTA.

How Zephyr Fusion ranks

  1. 1.Avalanche Energy56
  2. 2.Star Kinetics (Aetherflux-style space power)51
  3. 3.Star Power (Baiju Bhatt's space solar) — excluded, replaced by Helicity Space51
  4. 4.Rogue Space? no — Pulsar Fusion48
  5. 5.Zephyr Fusion47
Fix CTA
47Growth scoreupdated

category scores

CTA32Trust42Mobile web42Information hierarchy58Value props62
category scoresShowHide
CTA32Trust42Mobile web42Information hierarchy58Value props62

Score over time

656055504540Avalanche Energy 56 on May 10 (Wayback)Avalanche Energy 58 on Jun 10 (Wayback)Avalanche Energy 55 on Jun 18 (Wayback)Avalanche Energy 56 on Sep 20 (Live)Star Kinetics (Aetherflux-style space power) 49 on Mar 27 (Wayback)Star Kinetics (Aetherflux-style space power) 48 on Apr 11 (Wayback)Star Kinetics (Aetherflux-style space power) 48 on Apr 20 (Wayback)Star Kinetics (Aetherflux-style space power) 51 on Sep 20 (Live)Star Power (Baiju Bhatt's space solar) — excluded, replaced by Helicity Space 52 on Apr 10 (Wayback)Star Power (Baiju Bhatt's space solar) — excluded, replaced by Helicity Space 51 on May 22 (Wayback)Star Power (Baiju Bhatt's space solar) — excluded, replaced by Helicity Space 53 on Jun 9 (Wayback)Star Power (Baiju Bhatt's space solar) — excluded, replaced by Helicity Space 51 on Sep 20 (Live)Rogue Space? no — Pulsar Fusion 48 on Mar 30 (Wayback)Rogue Space? no — Pulsar Fusion 50 on Apr 21 (Wayback)Rogue Space? no — Pulsar Fusion 49 on May 10 (Wayback)Rogue Space? no — Pulsar Fusion 50 on Aug 22 (Wayback)Rogue Space? no — Pulsar Fusion 48 on Sep 20 (Live)Zephyr Fusion 47 on Sep 20 (Live)Sep 20

CTA

32Poor

Copy, size, verb, cost-feel — does the primary CTA earn the click?

Star Kinetics (Aetherflux-style space power)
Rogue Space? no — Pulsar Fusion
Avalanche Energy
LEARN MORE
Star Power (Baiju Bhatt's space solar) — excluded, replaced by Helicity Space

Problems

  • no CTA of any kind on the fold
  • mobile fold has zero actions
  • nav items are the only clickables
  • YC badge is passive, not a CTA

Trust

42Poor

Proof that the product is real, competent, and safe to try.

Zephyr Fusion
Avalanche Energy
Trust read
Zephyr Fusion"BACKED BY Y COMBINATOR" badge
Avalanche Energy"AVALANCHE ACHIEVES 1KEV — Measured Apparent Ion Temperatures Above 1 keV" announcement banner
Star Kinetics (Aetherflux-style space power)No visible trust signal identified.
Star Power (Baiju Bhatt's space solar) — excluded, replaced by Helicity SpaceNo visible trust signal identified.
Rogue Space? no — Pulsar FusionSunbird panel: "Get a glimpse into the future of propulsion with Pulsar Fusion's Sunbird Fusion Drive."

Mobile web

42Poor

The phone experience as a first-class citizen.

Mobile web annotations on the mobile capture12
  1. Headline over Earth edge — "In-orbit megawatt-class power" sits on the bright horizon gradient, weakening contrast on the lower lines.
  2. Sound off control — Tiny low-contrast gray label near the bottom edge is far below thumb-friendly tap size.

Information hierarchy

58Fair

Does the design help or inhibit what the page is trying to say?

Information hierarchy annotations on the desktop capture12
  1. Low-contrast section nav — ECONOMY, VISION, INDUSTRY, TEAM labels are dim grey on black and nearly invisible at a glance.
  2. Y Combinator badge — The only button-styled element in the fold is a credibility badge, drawing the click that a CTA should own.

Value props

62Fair

Title, subtitle, hero — do they sell the product's true value?

Zephyr Fusion’s headline undersellsZEPHYR FUSIONIn-orbit megawatt-class power

Working

  • Subhead names concrete category and scale
  • Hero shows the reactor firing, not decor
  • YC badge adds early credibility

Could improve

  • H1 is just the brand name
  • No customer or use case named
  • No proof points beyond YC badge

Competitors

inferred from product, audience, and value prop
#1Avalanche Energyavalanchefusion.com56 #2Star Kinetics (Aetherflux-style space power)aetherflux.com51 #3Star Power (Baiju Bhatt's space solar) — excluded, replaced by Helicity Spacehelicityspace.com51 #4Rogue Space? no — Pulsar Fusionpulsarfusion.com48
#5Zephyr Fusion47
—Star Catcherstarcatcher.spacefailed