# Debian 13 Nginx 1.29.3 add\_header don't show up on html page **URL:** \ **Category:** NGINX\ **Tags:** http3\ **Created:** [December 1, 2025, 2:51pm UTC](https://community.nginx.org/t/debian-13-nginx-1-29-3-add-header-dont-show-up-on-html-page/8444 "2025-12-01T14:51:26Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![HGA](https://avatars.discourse-cdn.com/v4/letter/h/f4b2a3/32.png) [@HGA](https://community.nginx.org/u/HGA)\ **Post date:** [December 1, 2025, 2:51pm UTC](https://community.nginx.org/t/debian-13-nginx-1-29-3-add-header-dont-show-up-on-html-page/8444/1 "2025-12-01T14:51:26Z")
I have tried different system configuration. Debian 13 with Nginx 1.29.3 and Debian 13 with Nginx 1.26.3. I have figured ot that no http3 header will be send to client. Here my default setup: ```auto server { ..... ## Enable HTTP/2 listen 443 ssl; http2 on; ## Enable HTTP/3 listen 443 quic reuseport; http3 on; add_header Alt-Svc 'h3=":443"; ma=86400'; ..... } ``` I also have checked that that no other `add_header` in or included into nginx.conf. What could be the reason that the header file not sent by Nginx. Thank you very much for your support. ---
**Author:** ![route443](https://avatars.discourse-cdn.com/v4/letter/r/838e76/32.png) [@route443](https://community.nginx.org/u/route443)\ **Post date:** [December 3, 2025, 4:14am UTC](https://community.nginx.org/t/debian-13-nginx-1-29-3-add-header-dont-show-up-on-html-page/8444/2 "2025-12-03T04:14:02Z")
Hi @HGA , I’m on Debian with 1.29.3 and everything works like a charm. I’d take a look at your full config, but I’d first check that: 1. You’re not using [add\_header](https://nginx.org/en/docs/http/ngx_http_headers_module.html) in your locations: > There could be several add\_header directives. These directives are inherited from the previous configuration level if and only if there are no add\_header directives defined on the current level. Inheritance rules can be redefined with the add\_header\_inherit directive (1.29.3). 1. `add_header` doesn’t add the header for all response codes, only for some of them ([https://nginx.org/en/docs/http/ngx\_http\_headers\_module.html#add\_header](https://nginx.org/en/docs/http/ngx_http_headers_module.html#add_header)). So you could try adding the `always` parameter. I don’t know which user agent you are using, but I’d test it with `curl`, for example like this: ```bash curl -I --http2 https://example.com/ ``` ---
**Author:** ![HGA](https://avatars.discourse-cdn.com/v4/letter/h/f4b2a3/32.png) [@HGA](https://community.nginx.org/u/HGA)\ **Post date:** [December 3, 2025, 4:55pm UTC](https://community.nginx.org/t/debian-13-nginx-1-29-3-add-header-dont-show-up-on-html-page/8444/3 "2025-12-03T16:55:38Z")
@route443 Here my curl results for http3 > HTTP/3 200 > server: nginx/1.29.3 > date: Wed, 03 Dec 2025 16:45:01 GMT > content-type: text/html > content-length: 615 > last-modified: Sat, 29 Nov 2025 13:05:24 GMT > etag: “692aef94-267” > alt-svc: h3=“:443”; ma=86400 > x-quic: h3 > accept-ranges: bytes But if I use [http3check.net](http://http3check.net) I’m getting ![grafik](https://d7a5pgbt9tjl6.cloudfront.net/original/2X/d/daaac16557b5ecead3d62e70da4dc0cfbd69d7e8.png) Is the curl answer correct? But I also can’t see any header in the source code `alt-svc: h3=“:443”; ma=86400`! And I use already always! The add\_header is direct under server! ---
**Author:** ![route443](https://avatars.discourse-cdn.com/v4/letter/r/838e76/32.png) [@route443](https://community.nginx.org/u/route443)\ **Post date:** [December 3, 2025, 9:01pm UTC](https://community.nginx.org/t/debian-13-nginx-1-29-3-add-header-dont-show-up-on-html-page/8444/4 "2025-12-03T21:01:17Z")
The HTTP response looks correct when using curl. However, the response in the case of [http3check.net](http://http3check.net) looks suspicious. Are you using any reverse proxy or CDN in front of nginx? ```auto Server: Apache Content-Encoding: gzip Keep-Alive: ...etc ``` In general, I’d check that nothing is modifying nginx’s response. ---
**Author:** ![HGA](https://avatars.discourse-cdn.com/v4/letter/h/f4b2a3/32.png) [@HGA](https://community.nginx.org/u/HGA)\ **Post date:** [December 4, 2025, 10:04am UTC](https://community.nginx.org/t/debian-13-nginx-1-29-3-add-header-dont-show-up-on-html-page/8444/5 "2025-12-04T10:04:23Z")
Hi @route443, you are right, it also confused me , that [http3check.net](http://http3check.net) is recognize the server as an `Apache server`. Totally I have currently running 4 Web server. Two Microsoft IIS and two Debian systems with Nginx, but no `Apache server`. The Debian servers should replace the IIS server. The server I currently talking about, is just the Debian System and Nginx 1.29.4 with an simple Nginx Welcome page, nothing else. Only in front of the server is a ``Sophos Firewall``. Can this be make some problems? Can I send you a private message with the URL of the page? How? ---
**Author:** ![route443](https://avatars.discourse-cdn.com/v4/letter/r/838e76/32.png) [@route443](https://community.nginx.org/u/route443)\ **Post date:** [December 4, 2025, 6:19pm UTC](https://community.nginx.org/t/debian-13-nginx-1-29-3-add-header-dont-show-up-on-html-page/8444/6 "2025-12-04T18:19:26Z")
Hi @HGA , I wouldn’t call myself an experienced sophos xg user, since I’ve only had limited experience with xg home. However, I remember that it does have the ability to publish internal apps to the external network using a waf/reverse-proxy mechanism. In any case, I could give some meaningful advice for OPNsense, but for Sophos I’d recommend setting up a simple port forwarding - say, 8443 TCP+UDP and reconfiguring nginx’s VS to listen on 8443 to rule waf factor out. If you go to my profile, there should be a ‘Message’ button - it looks like a private messaging feature 🙂 ---
**Author:** ![HGA](https://avatars.discourse-cdn.com/v4/letter/h/f4b2a3/32.png) [@HGA](https://community.nginx.org/u/HGA)\ **Post date:** [December 5, 2025, 8:26am UTC](https://community.nginx.org/t/debian-13-nginx-1-29-3-add-header-dont-show-up-on-html-page/8444/7 "2025-12-05T08:26:15Z")
I could get in touch with Sophos. They are not supporting HTTP/3 yet. It’s on there list, but with low priority! ---
**Author:** ![system](https://drob5swvtjqxg.cloudfront.net/user_avatar/community.nginx.org/system/32/19_2.png) [@system](https://community.nginx.org/u/system)\ **Post date:** [January 4, 2026, 8:26am UTC](https://community.nginx.org/t/debian-13-nginx-1-29-3-add-header-dont-show-up-on-html-page/8444/8 "2026-01-04T08:26:40Z")
Closed on January 4, 2026, 8:26am UTC This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.