Features:
- Encode multiple numbers - generate short IDs from one or several non-negative numbers
- Quick decoding - easily decode IDs back into numbers
- Unique IDs - generate unique IDs by shuffling the alphabet once
- ID padding - provide minimum length to make IDs more uniform
- URL safe - auto-generated IDs do not contain common profanity
- Randomized output - Sequential input provides nonconsecutive IDs
- Many implementations - Support for 40+ programming languages
Good for:
- Generating IDs for public URLs (eg: link shortening)
- Generating IDs for internal systems (eg: event tracking)
- Decoding for quicker database lookups (eg: by primary keys)
Not good for:
- Sensitive data (this is not an encryption library)
- User IDs (can be decoded revealing user count)
In your library add the following import:
import 'package:sqids/sqids.dart';Simple encode & decode:
final sqids = Sqids()
const id = sqids.encode([1, 2, 3]) // "86Rf07"
const numbers = sqids.decode(id) // [1, 2, 3]Note 🚧 Because of the algorithm's design, multiple IDs can decode back into the same sequence of numbers. If it's important to your design that IDs are canonical, you have to manually re-encode decoded numbers and check that the generated ID matches.
Enforce a minimum length for IDs:
final sqids = Sqids({
minLength: 10,
})
const id = sqids.encode([1, 2, 3]) // "86Rf07xd4z"
const numbers = sqids.decode(id) // [1, 2, 3]Randomize IDs by providing a custom alphabet:
final sqids = Sqids({
alphabet: 'FxnXM1kBN6cuhsAvjW3Co7l2RePyY8DwaU04Tzt9fHQrqSVKdpimLGIJOgb5ZE',
})
const id = sqids.encode([1, 2, 3]) // "B4aajs"
const numbers = sqids.decode(id) // [1, 2, 3]Prevent specific words from appearing anywhere in the auto-generated IDs:
final sqids = Sqids({
blocklist: {'86Rf07'},
})
const id = sqids.encode([1, 2, 3]) // "se8ojk"
const numbers = sqids.decode(id) // [1, 2, 3]