Bitwarden Slow Loading / Sync Issues — Possibly DNS + Routing Related (Cloudflare)

Ask the Community Password Manager
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1

Hi everyone,

I’ve been facing a serious performance and sync issue with Bitwarden, and after extensive debugging, I’ve narrowed it down to what looks like a DNS-dependent routing problem (likely involving CDN edge selection).

I’m posting this to check if others are experiencing the same issue — and if yes, it would really help if you could also report it to support, so this gets proper attention/escalation.

What’s happening

Across multiple platforms:

  • Web Vault (Brave / Firefox)

    • Login screen takes a long time to appear

    • Vault loading is extremely slow

  • Linux Desktop App

    • Vault takes a long time to load

  • iOS App

    • Sync fails or doesn’t trigger

    • “Sync Now” doesn’t work

(Full details + logs already shared with support: )

Key Finding (Very Important)

After testing with different DNS providers:

  • ISP DNS (Jio) → Works perfectly

  • Cloudflare (1.1.1.1 / 1.0.0.1) → Problematic

  • AdGuard → Works perfectly

  • Quad9 → Problematic

Simply switching DNS instantly fixes or breaks Bitwarden performance

Technical Observation

  • DNS resolution works fine (no NXDOMAIN/SERVFAIL)

  • But different DNS providers resolve different Fastly edge IPs

  • Some of these edges (especially via Cloudflare) show:

    • High packet loss

    • Timeouts

    • Broken routing

This suggests:

Not a Bitwarden bug directly
Not a pure ISP issue
But likely a routing / CDN edge selection issue influenced by DNS

Why this matters

  • This is not a local setup issue

  • It is reproducible

  • It affects core functionality (vault access & sync)

  • And currently, it may be silently impacting others without them realizing the cause

Request to the Community

If you’re facing slow Bitwarden loading or sync issues, please:

1. Test this quickly:

  • Switch DNS:

    • Try Cloudflare → then AdGuard or ISP DNS

  • Check if performance changes

2. If you notice the same pattern:

  • Please report it to Bitwarden support

  • Mention:

    • Your ISP

    • Location

    • DNS provider used

    • Performance difference across DNS

The more users report this pattern, the easier it becomes for:

  • Bitwarden

  • Fastly

  • Cloudflare

…to identify and fix the routing issue properly.

If anyone here has deeper networking insight or similar observations, would love to hear your findings.

Thanks.

2

If you want to increase the chances that community members take you up on your request, then you should probably provide more detailed instructions for this step:

3

@grb Thanks for pointing that out — makes sense.

If other users are also facing similar problems — like:

  • Web vault taking 1–2 minutes to load

  • Very slow login screen

  • iOS / Android app sync failing or not updating

…then the issue is very likely related to DNS.

What I found after debugging

From my testing:

  • Cloudflare DNS → Problematic

  • Quad9 DNS → Problematic

  • ISP default DNS (Jio in my case) → Works fine

  • AdGuard DNS → Works fine

So this doesn’t look like a general network issue — but something that changes depending on which DNS is used.

Public DNS you can try

You can test one DNS at a time:

  • Cloudflare

    • Primary: 1.1.1.1

    • Secondary: 1.0.0.1

  • AdGuard

    • Primary: 94.140.14.14

    • Secondary: 94.140.15.15

  • Quad9

    • Primary: 9.9.9.9

    • Secondary: 149.112.112.112

  • Google Public DNS

    • Primary: 8.8.8.8

    • Secondary: 8.8.4.4

How to test

  1. Change DNS to one of the above (one at a time)

  2. Restart browser or device (if possible)

  3. Open Bitwarden and check:

    • Login screen speed

    • Vault loading time

    • Sync behavior

If you’re not sure how to change DNS, just search:
“how to change DNS on [your device]”

How to confirm DNS actually changed

After changing DNS, it’s important to verify it. Search:
“how to check which DNS I am using”

(or use tools like nslookup / dig if you’re comfortable)

If you test, please share

  • Your ISP

  • Location

  • DNS used

  • Result (fast / slow / sync issue)

If multiple people see the same pattern, it will help confirm that this is a DNS-dependent routing issue, not just an isolated setup problem.

Similar reports (no clear root cause)

I also found multiple users reporting similar issues:

  • Slow vault loading / login delays

  • Extension stuck loading

  • Sync inconsistencies

Examples:

In most cases, there wasn’t a clear resolution.

From my debugging, this might be because:

The issue is actually DNS-dependent (routing-related) — not a simple app or cache problem.