Why does text look blurry on my monitor?
Usually a resolution or scaling mismatch rather than a fault, and the causes are distinguishable.
Not running at native resolution. This is the most common cause. LCD and OLED panels have a fixed physical grid of pixels, and they look sharp only when displaying exactly that many. Set anything else and the display must interpolate, spreading each image pixel across a non-integer number of physical ones — which is blurry by construction, unlike an old CRT which genuinely scaled.
Set the resolution to the panel's native figure. If text is then too small, adjust scaling rather than resolution.
Fractional scaling. Setting 125% or 150% scaling requires the system to draw at a size that does not map cleanly onto physical pixels. Integer scaling (100%, 200%) is sharp; fractional scaling is a compromise, and its quality varies substantially by operating system and application. Windows handles it better than it used to; some applications still render blurrily under it.
Applications not DPI-aware. Older programs declare no high-DPI support, so the system scales their output as a bitmap — sharp interface, blurry text. Windows offers a per-application compatibility override for this.
Subpixel rendering mismatch. Text rendering assumes a standard RGB subpixel layout. Panels using a different arrangement — some OLEDs, and many televisions — produce coloured fringing on text. Running ClearType tuning helps; it cannot fully fix a mismatched layout.
Connection and cable. An analogue VGA connection is inherently softer than digital, and a marginal or damaged cable at high resolution can cause softness. Use DisplayPort or HDMI, and try another cable.
TV-specific settings. Using a television as a monitor introduces overscan, which crops and rescales the image, and chroma subsampling, which blurs coloured text. Disable overscan and enable full RGB or 4:4:4 in the TV's input settings, often by naming the input as a PC.
Sharpening and motion processing on a TV should be turned off entirely.