Google I/O 2026 Gemini 3.5 and Spark Slow? Fix With Clash in 2026

What Google I/O 2026 changed for everyday Gemini users

Google’s opening keynote framed 2026 as the year Gemini becomes more agentic: faster default models, deeper integration with Google apps, and assistants that work in the background instead of only when you open a chat window. Three announcements matter most for networking and Clash configuration:

• Gemini 3.5 Flash is positioned as the fast, cost-efficient default—already replacing older Flash variants in the Gemini app and in Search’s AI Mode in supported regions. Users expect snappy first tokens; when the UI instead shows endless loading bars, frustration spikes because the product is marketed as “remarkably fast.”
• Gemini Spark is described as a personal agent that can reason across connected apps, surface proactive suggestions, and run tasks on your behalf with explicit user direction. Early access is tied to AI Ultra (U.S.-focused rollout to trusted testers, then wider beta for paying subscribers).
• Google AI subscription updates reshaped tiers: a new developer-oriented Ultra plan at roughly $100/month with higher limits, adjustments to the top-tier Ultra pricing, and bundled storage—meaning more users traverse billing and account portals in the same week they try Spark.

None of that requires exotic proxy features. It does require treating gemini.google.com, Google account sign-in, payments, and Generative Language API fronts as one coordinated bundle—especially when Spark’s background workers keep HTTPS sessions alive far longer than a single chat bubble.

How this differs from Gemini CLI and AI Studio routing

Our earlier Gemini CLI and AI Studio routing guide targets developers using aistudio.google.com, terminal clients, and API keys. After I/O 2026, many readers land on the consumer Gemini web app first—same Google account, different hostname mix and heavier real-time UI.

Keep the macro split from the DeepSeek + Gemini geography article if you run domestic models on DIRECT while steering Google traffic overseas. This page adds the I/O-specific surface area: Gemini 3.5 Flash as default, Spark agent enrollment, and AI Ultra checkout flows that never touch AI Studio at all.

Creative workloads such as Veo still belong in the Google Veo and Flow Labs routing piece. Overlap exists on shared Google CDNs, but agent chat on gemini.google.com should have explicit rows—not “maybe Labs rules cover it.”

Why gemini.google.com “keeps spinning” after I/O

The spinner is rarely one failed HTTP request. In practice you are juggling parallel traffic classes:

• Shell and assets for gemini.google.com—HTML, JavaScript bundles, fonts, and telemetry that may ride different subdomains than the model call itself.
• Authentication through Google account hosts (accounts.google.com, session cookies, device trust prompts) that must complete before Spark or Ultra features unlock.
• Model inference often reaching generativelanguage.googleapis.com or related *.googleapis.com endpoints with streaming responses and long idle gaps between chunks.
• Agent orchestration for Spark—additional polling, tool callbacks, and connected-app permissions that can open new hostnames after the first successful chat.
• Subscription gating via one.google.com, payments, or AI plan pages when users upgrade to AI Ultra to access Spark beta.

When only the marketing shell loads but inference stalls, Clash logs usually show two different policy groups for what feels like “one website.” Fixing that split is the core of reliable split routing for Google I/O 2026 features.

Hostname inventory: gemini.google.com, APIs, and AI Ultra

Google rotates edge names; treat this list as a starting inventory and confirm in your connection journal after reproducing a failure.

DNS alignment matters because Chrome may resolve through system DNS while background agent workers use different paths. If Clash enables fake-ip, walk through the DNS and fake-ip troubleshooting article until resolver answers match the connections you see in logs—misaligned DNS is a top cause of “works in incognito once, then spins forever.”

Build a GEMINI-IO policy group above GEOIP

Create a proxy-group—for example GEMINI-IO—with nodes you trust for long HTTPS sessions and moderate upload, not only download leaderboard scores. Patterns that survive agent-heavy 2026 traffic:

• url-test or fallback with conservative intervals so healthy nodes are not dropped mid-stream after one failed probe.
• A manual first hop while comparing Gemini 3.5 Flash web tests versus API curls.
• Separation from groups tuned for video CDN bursts (different regions and idle behavior).

Insert explicit DOMAIN rows for gemini.google.com, confirmed API hosts, and account or billing domains above coarse GEOIP matches and terminal MATCH. After every remote subscription refresh, re-check ordering—merged profiles often push Gemini calls into a noisy default pool.

# Replace GEMINI-IO with your proxy-group name
rules:
  - DOMAIN,gemini.google.com,GEMINI-IO
  - DOMAIN,accounts.google.com,GEMINI-IO
  - DOMAIN,generativelanguage.googleapis.com,GEMINI-IO
  - DOMAIN,one.google.com,GEMINI-IO
  # Add Spark / agent hosts your journal shows
  # ...
  - GEOIP,CN,DIRECT
  - MATCH,PROXY

Gemini Spark, agent APIs, and 24/7 session behavior

Gemini Spark is marketed as always-on help: proactive nudges, cross-app reasoning, and task execution under user control. Network-wise, that translates into more concurrent flows than a single chat thread—background sync, permission prompts for connected apps, and retries when a tool call stalls.

For node selection, optimize for:

• Idle tolerance—agents pause between tool steps; nodes that reset quiet TLS sessions after 30–60 seconds look like “Spark froze.”
• Upload headroom—screenshots, files, and multimodal turns upload on every user message.
• Consistent egress—switching countries mid-session can invalidate risk checks or trigger extra re-auth.

If you also run coding agents in terminals, compare discipline with the Claude Code and MCP routing guide: Spark is first-party Google traffic, but the same lesson applies—background child processes must inherit the same policy as the visible browser tab.

AI Ultra subscription and Spark beta enrollment

Spark’s rollout is tied to Google AI Ultra and regional availability. Users often fixate on “beta not enabled” when the real blocker is a payments or account page that never finished loading through the same egress as gemini.google.com.

While testing Ultra enrollment:

1. Open AI plan pages in a clean browser profile with Clash logging enabled.
2. Note every new hostname during checkout and post-purchase confirmation.
3. Add those domains to GEMINI-IO before retesting Spark visibility.
4. Confirm your Google account country matches supported Spark regions—routing cannot bypass hard product geo-fences, but it eliminates false negatives from half-loaded billing UI.

Remember Google’s own staged rollout: trusted testers first, then broader AI Ultra beta. Stable routing lets you distinguish “not invited yet” from “page never loaded.”

TUN, mixed port, and double-proxy traps

The Gemini web app runs in Chrome; Spark’s background behavior may involve service workers or companion processes that ignore system proxy tables unless TUN mode captures them uniformly.

• TUN—broadest coverage for agent workers; test with a short chat plus five minutes idle to catch session drops.
• System proxy + mixed port—narrower blast radius; ensure no second VPN or corporate proxy stacks on top of Clash.
• Browser-only extensions that split-DNS certain domains can fight Clash fake-ip—disable during bisect.

For terminal-side Google tooling still in your workflow, keep terminal HTTP proxy settings aligned with Clash so HTTPS_PROXY does not nest another hop in front of GEMINI-IO.

Symptom → fix matrix for Gemini 3.5 and Spark

FAQ

Gemini 3.5 Flash works in Search but gemini.google.com still spins—is that Clash?

Often yes. Search AI Mode and the Gemini web app do not always share identical hostnames. Log both sessions and ensure model calls land in the same GEMINI-IO group.

Why does Gemini Spark beta never appear even with AI Ultra?

Check regional rollout first, then routing. Half-loaded plan or account pages are common when billing hosts use a different policy than chat. Align them before opening a support ticket.

Should I route all of googleapis.com for Spark?

No—start surgical. Add API hosts your agent turns actually hit, then expand from evidence in connection logs.

Checklist before you blame Google’s status page

Stop I/O hype from turning into endless spinners

Browser-only VPN extensions and “one-click global” tools often excel at loading a landing page once, then fall apart when Gemini Spark keeps background HTTPS alive, billing iframes hit a different path, or Gemini 3.5 Flash streaming sits idle between tool steps. You end up toggling regions blindly while logs stay opaque.

Clash is built for exactly this kind of 2026 AI stack: ordered split routing rules, a dedicated GEMINI-IO policy group for gemini.google.com and confirmed API hosts, per-flow visibility into which YAML row matched, and node selection you can tune for agent sessions instead of speed-test vanity metrics. Once web, billing, and inference share one deliberate egress story, most “Google broke Spark” reports shrink into ordinary DNS or policy fixes.

If you want Google I/O 2026 features to feel as fast as the keynote promised, download Clash for free and codify these rules once—then every new Gemini rollout stays a routing tweak, not a network mystery.