After effects how to render in full quality with a custom resolution

[Marino2023MG]

Hi, im trying to render my animation in custom sizes such as 

672x 480

576x384

but the exports look blurry . This is for the company im working on so its important for me to have good quality. Is it possible or because my aspects are the above i cannot have full hd.

So far i have tried adobe media encoder match source high vibrate

And the after effects renderer in h.264 . All the 3 different render options I tried  come out as poor quality.

Please let me know if you know any way to render without losing my quality

[Mylenium]

It would help if you actually showed comparative screenshots and provided the exact render settings.

Mylenium

[Marino2023MG]

these are some of the settings I tried

[Rick Gerard]

By today's standards, those are small files. 1/4 the resolution of the most basic computer monitor and a little less than 1/4 the resolution of a mobile phone. If your Media Player or YouTube displays the render any larger than about 1/4 of the screen, the video is going to be scaled up and look bad. The only way to really judge the final quality is to open the rendered file in After Effects or Premiere Pro and set the playback resolution to auto and the Magnification Ratio to 100%. 

To get accurate pixel-for-pixel interpolation, your comps should match the size of the final render. The only reason they would look blurry is if your horizontal and vertical lines do not match up with the pixel grid, the comp size matches the render size, and the playback is not scaled up.

A screenshot or a sample file would let us know if there are color issues caused by banding in 8-bit files. 

[Marino2023MG]

Ty very much this was my guess as well. Because the sizes are low the resolution would be low as well.