I have light brown hair and accidentally died it black. How do I get it back to brown? I have tried just brown dys but they just stay the same or make my hair darker. So is there any way to fade it out QUICKLY or dy it back to a similar color without bleaching it first?

You could try using clarifying shampoos to fade it out.

There are also hair colour removers available. L'oreal colour zap is a popular brand.
If you do use it, remember your hair will be left looking a bit brassy so dye it to the colour you want.

Keep in mind that black hair color is the hardest to fade or remove. Permanent hair color will gradually fade over time, but it will not fade your hair to brown or light brown. If you want go from black to light brown, minus the red/orange shade, it's best pre-lighten your hair with bleach and then deposit the desired color. Another option is to use a 30-volume peroxide developer with your selected hair color in equal parts to achieve results. To avoid red/orange tones, choose a neutral or ash hair color.