iiinova — where your digital self keeps evolving

Tim Kadlec @tkadlec.bsky.social · 15/07/2026

My talk from last year's @perfnow.nl is now out. Come for the dad jokes & advice on how to troll your kids, stay for my thoughts on stubborn empathy for our users as the foundation for web perf & two threats to the web: the monoculture and the machine. www.youtube.com/watch?v=Dvpi...

youtube.com

Stubborn Empathy - Tim Kadlec - performance.now() 2025

YouTube video by Web Conferences Amsterdam

3153

Tim Kadlec @tkadlec.bsky.social · 18/05/2026

📝 New post: Losing Focus timkadlec.com/remembers/20... Expressing some concerns I have about how all the AI-buzz is causing our industry to lose focus on what matters: the actual human beings using what we build.

2162

Tim Kadlec @tkadlec.bsky.social · 04/05/2026

I wrote "Your Voice" in 2016 to encourage people new to speaking & writing to be yourself, to find what's authentic for you and make sure you let that shine through in what you create. Seeing so many social posts and blog posts clearly written by AI—it feels more important today than 10 years ago.

timkadlec.com

Your Voice - Web Performance Consulting | TimKadlec.com

1103

Tim Kadlec @tkadlec.bsky.social · 17/04/2026

I'm very excited about this! Have seen some really significant impact in our tests. With the sizes of websites and JS payloads continuing to increase, this is both important and impactful.

0309

Reposted by Tim Kadlec

Patrick Meenan @patmeenan.com · 17/04/2026

Really excited to see the support for compression dictionaries that @cloudflare.social is working on. Great background on the feature as well.

043

Tim Kadlec @tkadlec.bsky.social · 26/03/2026

p75 and p90 JavaScript bytes on the web have exploded since May, 2025—easily the largest 10 month period based on HTTP Archive data since 2023. The long-tail is getting worse, very quickly. Gemini, what happened in May 2025?

69442

Tim Kadlec @tkadlec.bsky.social · 20/03/2026

Doing my part to keep customer support people employed and paid one annoying and frustrated "please let me talk to a real person and never make me use this useless AI support again" message at a time.

060

Tim Kadlec @tkadlec.bsky.social · 05/03/2026

The somewhat ironic part about all the backlog of code to review thanks to AI coding tools is that AI is _significantly_ better at code review than it is at code generation.

070

Tim Kadlec @tkadlec.bsky.social · 28/01/2026

Do I know anyone, or does anyone I know know anyone, at eBay who I can chat with about some things I'm running into with their API's?

002

Tim Kadlec @tkadlec.bsky.social · 26/01/2026

AI automated support bots are one of the worst plagues to infest the internet. They are truly awful, infuriating and useless 95% of the time. Please, I am begging, just let me talk to a real person.

2160

Tim Kadlec @tkadlec.bsky.social · 08/01/2026

AI will have to pry em dashes out of my cold dead hands Interesting conversation I had with my kids recently: my high-school daughters actively avoid using "big" words in their writing because they get accused of using ChatGPT. Literally dumbing down their writing to avoid being accused of using AI

1252

Tim Kadlec @tkadlec.bsky.social · 12/12/2025

I do firmly believe that if you're an individual or company that is NOT over-indexing on AI right now, you have the competitive advantage. Unfortunately I do not have high hopes that the industry will recognize that until significant damage has been done.

0153

Reposted by Tim Kadlec

Sergey Chernyshev @sergeyche.dev · 06/11/2025

Very happy to work on a tool like that with @tkadlec.bsky.social and the team! Please try it out and post the issues and PRs.

091

Tim Kadlec @tkadlec.bsky.social · 01/11/2025

At the airport heading back after another incredible #perfnow. Each year, I'm reminded of how fortunate I am to be a part of the performance community. So many wonderful, kind, smart people all working together to make the web better. Already looking forward to next year.

0140

Reposted by Tim Kadlec

performance.now() conference @perfnow.nl · 01/11/2025

performance.now() 2026 will take place on 19th and 20th of November 2026. #perfnow.

0277

Tim Kadlec @tkadlec.bsky.social · 31/10/2025

Always, always happy to see @yoav.ws get a shout-out. So much incredible work has happened because of him. Most recent example—speculation rules in WebKit. #perfnow

1243

Tim Kadlec @tkadlec.bsky.social · 31/10/2025

Telescope, the new cross-browser performance testing agent I mentioned at #perfnow that we @cloudflare.social have open-sourced is here: github.com/cloudflare/t... We want this to be a tool the entire community is able to contribute to and benefit from, so please help us make it better!

github.com

GitHub - cloudflare/telescope: Cross-browser web performance testing agent

Cross-browser web performance testing agent. Contribute to cloudflare/telescope development by creating an account on GitHub.

5385

Tim Kadlec @tkadlec.bsky.social · 31/10/2025

I have been sooooo looking forward to this! SPA heuristics are gonna be such a huge step forward for measuring perf on the web and finally having hard data on the perf impact. @mmocny.com #perfnow

Michal Mocney presenting at perfnow about SPA heuristics, demoing being able to measure LCP and other metrics on soft navigations

0132

Reposted by Tim Kadlec

Stoyan Stefanov @stoyan.me · 30/10/2025

Fellow #perfnow fellows, a reminder that PerfPlanet calendar is coming this December for another edition. And it needs YOU. Please ask if you have any contribution ideas or concerns calendar.perfplanet.com/contribute/

calendar.perfplanet.com

Contribute

Passionate about a topic? Working on a new tool? Have a technique you want to teach? Research you've done? Tell the web performance community! Send your articles to ssttoo@ymail.com. Please include: ...

22319

Reposted by Tim Kadlec

Phil Hawksworth @philhawksworth.dev · 30/10/2025

“We should treat accessibility as something that is structural or baked in or part of the DNA, if we want to be successful” — says @marcysutton.com at #perfnow “Don’t treat it like trying to put chocolate chips into a cookie after it is baked” I love this framing!

1469

Tim Kadlec @tkadlec.bsky.social · 30/10/2025

@inesakrap.bsky.social starting her #perfnow talk with Lego's and Bluey has me already a fan.

082

Reposted by Tim Kadlec

Tammy Everts 🍁 @tammyeverts.com · 30/10/2025

Slides from my @perfnow.nl talk — How Fast Is Fast Enough? — are up! If you’re at #PerfNow (or even if you’re not) I’d love to talk about creating a delightful experience for your users. speakerdeck.com/tammyeverts/...

speakerdeck.com

How Fast Is Fast Enough? [PerfNow 2025]

It sounds like a simple question, but if you've been working in web performance long enough, you know the answer is far from straightforward. In this ke…

0116

Reposted by Tim Kadlec

Estela Franco @guaca.bsky.social · 30/10/2025

Friendly reminder! #perfnow

Harry on the stage. Behind him, a slide that reads as follows:

"While a good TTFB doesn't necessarily mean you will have a fast website, a bad TTFB almost certainly guarantees a slow one."
— csswz.it/ttfb

172

Reposted by Tim Kadlec

Vinai Kopp @vinai.bsky.social · 30/10/2025

@tammyeverts.com opening #perfnow with How fast is fast enough? #pragmagical

092

Reposted by Tim Kadlec

beyond tellerrand @beyondtellerrand.com · 17/10/2025

It is Friday, end of week. A good time to grab your ticket for #btconf Berlin. 3 weeks to go and we still have seats available. Full list of #speakers, their #talks and #schedule here on our website. beyondtellerrand.com/events/berli...

beyondtellerrand.com

beyond tellerrand // BERLIN 2025, taking place 06 - 07 Nov 2025

beyond tellerrand 2025 in Berlin. Join us on 06 - 07 Nov 2025 for talks about web, design, technology, typography and much more. In the renowned friendly atmosphere.

025

Tim Kadlec @tkadlec.bsky.social · 15/10/2025

This is super exciting, particularly knowing Safari has it in Tech Preview so we're _this_ close to having it cross-browser. Also fun to watch the rollout through the lens of Cloudflare's Web Analytics.

061

Tim Kadlec @tkadlec.bsky.social · 08/10/2025

If your industry would die if you did the right thing perhaps it's not a good industry?

0254

Tim Kadlec @tkadlec.bsky.social · 02/10/2025

New case study on wpostats.com Relive improved LCP by 50% and cut out layout shifts and saw a 3% increase in conversion rate, 6% decrease in bounce rate and 9% increase in page views per session. wpostats.com/2025/10/02/r...

041

Tim Kadlec @tkadlec.bsky.social · 15/09/2025

Been a hot minute, but working through some of the case studies that were submitted to wpostats.com but not yet put live. Starting with a pair of INP-relevant studies from PubTech and ContentSquare. wpostats.com/2025/09/15/p... & wpostats.com/2025/09/15/c...

wpostats.com

Consent Management Platforms (CMPs) are tools that help websites comply with privacy regulations by obtaining user consent for the use of cookies and tracking technologies. In addition to the primary ...

040

Tim Kadlec @tkadlec.bsky.social · 02/07/2025

👀 Safari plans to ship LCP and INP in 2025?! Be still my beating heart. webkit.org/blog/16458/a...

160

Tim Kadlec @tkadlec.bsky.social · 01/07/2025

This is incredible data from @dbelson.com showing HTML requests from crawlers versus referrals from that platform. Very easy to see the cost of AI here. ClaudeBot: 70.9k requests : 1 referral (!!!) OpenAI: 1.6K : 1 Perplexity: 202.4 : 1 blog.cloudflare.com/ai-search-cr...

0105

Tim Kadlec @tkadlec.bsky.social · 26/06/2025

Pumped for this. The line-up is stacked (with more coming soon) & the community around the event has gotten better and better each year with amazing conversations throughout, side events, large standards & browser involvement—it's wild to think about how this has taken off from its 1st year.

072

Tim Kadlec @tkadlec.bsky.social · 22/06/2025

Lake Superior remains undefeated

1220

Tim Kadlec @tkadlec.bsky.social · 06/06/2025

For those of you who watched my talk at @webexpo.bsky.social, the bug I mentioned regarding speculation rules and GET/POST looks like it should be fixed in Chrome v138. chromium-review.googlesource.com/c/chromium/s... h/t @tunetheweb.com

chromium-review.googlesource.com

Gerrit Code Review

050

Reposted by Tim Kadlec

Tammy Everts 🍁 @tammyeverts.com · 30/05/2025

Thanks again to everyone who came to my #WebExpo talk about the intersection of site speed, #UX and business metrics – and how to make a data-driven business case for investing in #webperf. My slides are up. I'd love to hear your questions and feedback! speakerdeck.com/tammyeverts/...

speakerdeck.com

Connecting the Dots Between Site Speed, User Experience & Your Business [WebExpo 2025]

What do the most successful websites have in common? They’re all fast. Faster sites have happier users. Those happy users visit your site more often and…

0103

Tim Kadlec @tkadlec.bsky.social · 30/05/2025

Heading home after a great #webexpo with a nice mix of old friends and new. Doesn't hurt that Prague is beautiful with ample dessert options. :)

3100

Tim Kadlec @tkadlec.bsky.social · 26/05/2025

In all my years of flying, my luggage has been lost three times and three times only. I have been to Prague three times and three times only. The venn diagram is a full circle.

4260

Tim Kadlec @tkadlec.bsky.social · 09/04/2025

I'm just a guy, sitting in front of his computer, begging companies to please stop making me talk to AI "support" and let me talk to an actual human being instead.

4422

Tim Kadlec @tkadlec.bsky.social · 31/01/2025

Been wondering why a bunch of sites have been SUPER slow lately. Turns out it's the @1password.bsky.social chrome extension doing really bad things. :/ Gonna have to disable for awhile.

Chrome's performance timline, showing a 3.99s long task caused by a script injected by the 1Password Chrome Extension.

Screenshot showing the chunk of code (a mutation obsever) in the 1Password extension that seems to be the culprit.

4468

Tim Kadlec @tkadlec.bsky.social · 07/01/2025

One thing about deadlifts: if you get sloppy with your form, you'll be _painfully_ aware of it. This message has been brought to you by lower back pain.

0120

Tim Kadlec @tkadlec.bsky.social · 25/12/2024

Drinking plenty of mulled wine and watching Rudolph, as our forefathers intended.

1110

Tim Kadlec @tkadlec.bsky.social · 17/12/2024

This is so well deserved. Not only is Pat one of the most brilliant people I've ever had the opportunity to work with, but he's so generous with his time—I wouldn't be able to do what I do without all the times over the years that Pat patiently answered my questions and helped me figure things out.

0215