# Understanding abstol and reltol in DifferentialEquations.jl

**URL:** <https://discourse.julialang.org/t/understanding-abstol-and-reltol-in-differentialequations-jl/129250>\
**Category:** General Usage\
**Tags:** differentialequation\
**Created:** [May 22, 2025, 4:47pm UTC](https://discourse.julialang.org/t/understanding-abstol-and-reltol-in-differentialequations-jl/129250 "2025-05-22T16:47:53Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![danielwe](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/danielwe/32/35657_2.png) [@danielwe](https://discourse.julialang.org/u/danielwe)\
**Post date:** [May 22, 2025, 5:12pm UTC](https://discourse.julialang.org/t/understanding-abstol-and-reltol-in-differentialequations-jl/129250/2 "2025-05-22T17:12:27Z")

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Just linking for reference an in-depth discussion about abstol and reltol from a few months ago: [Setting `abstol` and `reltol` when solving the Schrödinger equation with OrdinaryDiffEq](https://discourse.julialang.org/t/setting-abstol-and-reltol-when-solving-the-schrodinger-equation-with-ordinarydiffeq/125534) (note that the answer that’s marked as correct isn’t 100 % correct, so don’t stop reading there).

I have no idea why lowering the tolerance makes your solver unstable, though. Probably a good idea to experiment with different solvers, but it would also be good to know why the default choice screws up like this.

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