A lot think that Bitcoin is anonymous. No! It's not, it's only pseudonymous. Every bit of Bitcoin transactions can be traced thus, all points of exchange between parties can be investigated with the help of blockchain analysis tools. 

The blockchain (also known as Distributed Ledger Technology, DLT) on which Bitcoin was built allows all Bitcoin activities to be recorded and easily accessible to the public. Some people don’t like this idea and Bitcoin tumblers help make their wish of leaving a clean trace after each transaction possible.

What are Bitcoin Tumblers or Bitcoin Mixers

Bitcoin tumblers (also known as Bitcoin mixers) is a service that disrupts the connection between a bitcoin wallet address that is sending Bitcoin (source) and an address receiving Bitcoin (destination). They do this at a low transaction fee, making you practically anonymous, therefore, with a bitcoin tumbler, you can make bitcoin origin obscure, and thus, ill-gotten bitcoin can be made clean. There's no law that bans the use of Bitcoin tumblers so it's not illegal.

There are a lot of Bitcoin mixer websites and applications across the globe and one must be careful on which to trade on as not all are safe and secure to trade on. Some reliable Bitcoin tumblers are:

Chipmixer

Source: Chipmixer

Chipmixer is a bitcoin tumbler that has already-funded bitcoin addresses with "chips" of different bitcoin sizes including 0.001 BTC, 0.002 BTC, and so on. Once they receive bitcoin to be tumbled, they send "clean" chips that can be merged to provide an equal quantity of the bitcoin sent assures transaction fee (which is relatively low).
Clearnet address: chipmixer.com
Onion address: chipmixorflykuxu56uxy7gf5o6ggig7xru7dnihc4fm4cxqsc63e6id.onion
Fee: Pay what you want
Minimum: 0.001 BTC

Wasabi Wallet

Source: Wasabi Wallet

Wasabi Wallet is a wallet that has a high level of privacy. Coinjoins are built in to allow easy and quick mixing of bitcoin. It is a well-recommended tumbler. The minimum quantity of bitcoin that can be mixed in a wasabi wallet is 0.1 BTC. The transaction fee charged is very low. It is simple and easy-to-use.
Clearnet address: wasabiwallet.io
Onion address: wasabiukrxmkdgve5kynjztuovbg43uxcbcxn6y2okcrsg7gb6jdmbad.onion
Fee: 0.003%
Minimum: 0.1 BTC

Samourai

Source: Samourai

Samourai is a modern bitcoin wallet with the aim of keeping users' transactions identity secure and private. Samourai charges one of the lowest fees and ensures quick transactions without paying much and it also works under any network conditions. Transaction on Samourai only involves you keeping your private keys. You don't have to register with any ID or personal addresses.
Clearnet address: samouraiwallet.com/whirlpool
Onion address: 72typmu5edrjmcdkzuzmv2i4zqru7rjlrcxwtod4nu6qtfsqegngzead.onion
Fee: flat fee for unlimited anonymity
Minimum: N/A

If you want to leave no trace after your bitcoin transactions, using a bitcoin mixer is a great option.

These bitcoin mixers have premixed bitcoins that they send to users. All you need do is create an account or just make a session on their platform and send them your bitcoin and you'll receive 'clean' same-quantity bitcoin.

What other Bitcoin tumblers you knew? Let us know in the comment section.