Staying Under a Character Limit Across Different Platforms
Different platforms enforce very different character limits — a standard SMS segment is commonly 160 characters, various social platforms enforce their own limits (which change periodically), and form fields (a bio, a meta description) often have their own specific constraints — checking the exact current limit for the specific platform, rather than assuming, is the reliable approach.
Character limits vary enough across contexts that memorizing a single number and applying it everywhere is a common source of content that unexpectedly gets cut off or rejected.
Why limits vary so much by platform
Each platform sets its own limit based on its own display design, technical constraints, and product decisions — these limits also change over time as platforms evolve, which is why relying on a remembered number from months or years ago can be outdated.
A practical habit for staying within limits
Checking a character counter before finalizing content for a specific platform, rather than estimating by eye, avoids the common experience of content being unexpectedly truncated or rejected right at submission — especially useful for content with special characters or emoji, which can count differently than expected.
Building in a buffer
For anything close to a limit, leaving a small buffer rather than writing to the exact maximum protects against small differences in how a platform counts certain characters (as covered in the characters-vs-bytes guide) or against needing to add a small addition later without going over.