I’ve checked that both URLs are accessible, both images are under 10MB, and both have valid JPEG format. The URLs work fine when opened in a browser. Has anyone experienced this issue before? What could be causing some URLs to work while others don’t?
I faced a similar issue when developing my Telegram bot. The root cause usually lies in SSL certificate problems or latency from the image source. Telegram expects quick responses, and if the image server doesn’t deliver promptly, it can lead to that misleading “wrong file identifier” message. To mitigate this, I implemented a quick HEAD request before sending the image to confirm its accessibility. If the response takes longer than 3-4 seconds, I’ve noticed it commonly leads to failures. Additionally, ensure your CDN doesn’t impose restrictions on user agents, as that can prevent Telegram from accessing the URLs.
This usually happens because of wonky HTTP headers that mess with Telegram’s image fetcher. Your CDN might be sending different Content-Type headers or missing Content-Length for the same image formats - Telegram gets picky and rejects URLs that look identical to you. I ran into this with dynamic image URLs that had session tokens or timestamps. Fixed it by adding middleware that cleans up headers before serving images to Telegram. Also check if your CDN has geo-restrictions - Telegram’s servers might hit different CDN nodes with different configs. Try running wget from different IP ranges to see if you’re getting consistent headers and response codes.
Had this exact problem last month. Some image hosts block Telegram’s IP ranges or have random rate limiting - that’s why it works sometimes but not always. Try a different CDN or add proper cache headers to your images. Fixed it for me.
Been dealing with this for years. It’s not just URL encoding or SSL certs.
Telegram’s servers are weird about image URLs compared to browsers. They validate requests differently. The same CDN endpoint might work one day and fail the next based on server load or routing.
Stop fighting Telegram’s URL validation. Download the image first, then upload it as a file. Kills all the URL headaches.
I built automation for this whole process. Fetches images from any URL, validates locally, then uploads to Telegram properly. No more random failures or weird errors.
Runs on Latenode and handles image processing, retry logic, and proper uploads. Way more reliable than hoping Telegram fetches your URLs.
This happens when Telegram’s servers can’t fetch your image, even though it loads fine in your browser. I’ve seen this a lot - usually it’s URL encoding issues. Special characters in query parameters or hash fragments can break things for Telegram while browsers handle them just fine.
Check your URL encoding first, especially any weird characters. Also, some CDNs send different headers or redirects when Telegram’s bot hits them versus a regular browser. Try testing your URLs with curl using Telegram’s user agent - you might see different responses.
If that doesn’t work, switch to POST requests with the URL in the body instead of GET parameters. That usually fixes the inconsistencies.