I have had this problem for years and have had to use other text overlay applications in the past. Now I MUST get to the bottom of this! Please let me know how I fix this issue! The crisp font is a screen capture of the Photoshop file open in Photoshop. The blurry screen capture is from the saved file. I have tried all I know to and am at a complete loss!
Thin text like this wil lalways look slightly blurry when converted to JPEG. It's an inherent limitation in how the compression works. A PNG should not change the visual appearance that much, but it's unclear which save settings you actualyl used, what your resolution is, what your text antialaising is set to. Cropped image snippets are not useful without that info.
It not possible to answer you question from what you posted. You did not state at what zoom percentage you captured part of Photoshop screen or how you save the image file the file type and quality. You failed to state what image viewer you use that part of its display. I open both of you captures in Photoshop inverted the blurry one and dragged it on top of the sharp image and lowered the new layer's opacity. The image do not line up they are not even the same size.
Your question clearly explained the issue, and the screen shots you included demonstrate the problem perfectly. The other answers say that you have not provided them with enough information, but it would be virtually impossible to send them every single setting you used. Unfortunately, I do not have the answer, as I found this post because I have the same question. I often do screen captures of web page text from Chrome. Paste into a new Photoshop PSD, at the default resolution of 72 (if I make it higher, the image blurs). I crop it. At this point in Photoshop, the text is crisp and clear. I then save it as a jpg at the highest size (12). The end result is a bit blurred. Same thing when I try a .png. My guess is there is a setting I'm missing or forgetting about.
Just to add to this, I am also having this problem and have not yet found a solution. I figured something was wrong or there was a setting I was overlooking when I also tried saving to .png and had the same blurry text issue since it is not compressing anything. Also, this is a relatively new issue for me so it might have something to do with one of the more recent updates.
If you look at the original example at the top, you will see that the one on the right is not reproduced at 100%. It is slightly smaller. In other words, it is scaled, perhaps by "responsive" site design, and scaling always means softening.
Unless one image pixel is represented by exactly one screen pixel, it will be soft and blurry.
Ppi is a red herring. Ppi does not apply on screen, it is completely irrelevant. Ppi is strictly a print parameter. This is only about pixels, nothing else.