MAX channel avatars and images on datool.ru are now served via a CDN
Channel avatars, post images and category pictures on datool.ru are now delivered by a content delivery network (CDN) from media.datool.ru: WebP files, small avatars for lists and lazy loading make pages open faster.
All images on the datool.ru showcase — MAX channel avatars, pictures from posts, category covers and documentation screenshots — are now delivered through a CDN, a content delivery network. Your browser receives each file from media.datool.ru via the nearest node of the network instead of fetching it straight from storage. Along with this, every copy is now stored as WebP, lists use small avatars, and images below the fold load lazily.
Why it matters: a catalog page, a ranking or "Today in MAX" shows dozens of channels at once, each with its own avatar. Images used to be the heaviest part of such pages. Now they weigh less, reach the browser faster and no longer hold back the text and numbers you actually opened the page for.
What a CDN is and why we use it
A CDN (content delivery network) is a set of servers that keep copies of files and hand them out to visitors. When you open a channel page, the avatar comes not from the main storage but from a CDN node that already has it in cache. The storage does not have to answer every request, and the visitor gets the picture sooner.
This matters to us for three reasons:
- Speed. A CDN node serves the file from its cache without a round trip to storage; repeat visits also take images from the browser cache.
- Resilience. Peak load — for example, when many people open a popular channel at the same time — falls on the delivery network rather than on the storage.
- One address for everything. All images live under
media.datool.ru, and the API returns the same address: the avatar field of a channel card points to our copy served via the CDN.
The original copies are stored in Russia in object storage, and the website itself runs on servers in Moscow.
Which images go through the CDN
- MAX channel and bot avatars. We copy an avatar as soon as we read the channel card and keep it permanently. If the owner changes the avatar in MAX, the old copy is deleted and a new one appears.
- Post images. For posts younger than 7 days, the preview is prepared right after collection. For older posts, the copy is made the first time someone actually opens the picture — from the next view on, it is served by us.
- Category images. Category pictures in the category catalog and on category pages are stored in two sizes, up to 800 and up to 500 pixels.
- Documentation screenshots and blog covers. Illustrations on docs.datool.ru also live in storage and are served via the CDN.
WebP and sensible sizes
Every copy is saved as WebP, which produces a noticeably smaller file than JPEG or PNG while looking the same on screen. Sizes match the way each image is displayed:
- post image preview — up to 800 pixels on the long side;
- channel avatar — up to 320 pixels for the channel header and the post page;
- small avatar copy — up to 96 pixels for lists;
- category images — up to 800 and up to 500 pixels, keeping proportions.
Smaller pictures are never stretched: if the original in MAX is below the limit, the copy keeps its original size.
Small avatars for lists
In the catalog, in rankings, and on the "MAX statistics" and "Today in MAX" pages, an avatar is a circle 26 to 48 points wide. Serving a 320-pixel copy for it was wasteful. So from every downloaded picture we also make a small copy of up to 96 pixels — still a sharp circle on a high-density screen.
Such a copy weighs 1–2 KB instead of 3–30 KB. On the "Today in MAX" page, avatars used to add up to about 0.75 MB; now they are roughly ten times lighter. The channel header and the post page still show the large avatar, where it is actually needed.
Lazy loading: what is on screen comes first
Images visible right after the page opens load first: the "Leaders of the day" winners, the first ten cards of the channel catalog and the first rows of rankings. Everything below the screen or on hidden tabs is loaded by the browser as you scroll. The top of the page appears sooner, and images you never scroll to do not use up your data.
If an avatar fails to load on the first try, the site requests it again; if the retry fails too, you see a neat plain circle instead of a broken-image icon.
What we do not copy
- Images from private channels. We never put them into public storage — on a private channel page, which only its owner sees, images are shown via the MAX link.
- Video, audio and files. Video plays directly from MAX servers; we only keep a preview frame.
- Deleted posts. When a post is deleted in MAX, we erase it from our database together with its image copies.
Who benefits
- Showcase visitors — pages with long channel lists open faster, especially on phones and mobile internet.
- Channel owners — the channel's avatar and images on datool.ru look tidy and do not disappear when a temporary MAX link expires.
- Developers — in the API, the avatar field points to a permanent copy served via the CDN, which you can safely display in your own interfaces.
Frequently asked questions
Do I need to configure anything for images to go through the CDN?
No. It works on its own: the site links to media.datool.ru, and the browser receives files from the delivery network nodes. There is nothing to turn on or install.
Why does an image in an old post sometimes appear with a delay?
Copies of images from posts older than 7 days are made on first view. Until the copy exists, the site shows the original picture from MAX or a "Loading image…" placeholder and swaps in the copy once it is ready.
Why does a channel's avatar differ from the one in MAX?
The copy is refreshed the next time we read the channel card. If the owner has just changed the avatar, the new picture appears after the next card update, and your browser may keep showing the old one from its cache for a while.
Are images from private channels available via the CDN?
No. We do not copy images from private channels into storage and do not serve them via the CDN.
Summary
According to datool.ru, the showcase lists hundreds of thousands of open MAX channels, and almost every one has an avatar. All these images now arrive through a content delivery network, in WebP and at the size the screen actually needs. Open the channel catalog or a channel page and judge the speed yourself. For how the service started, see the datool.ru launch news.
