Who is better? Who is more serious? In my view, Upwork.com is simply in another league. Upwork is a serious company while Freelancer.com is close to scamming both companies and freelancers.
That being said, what is wrong with Freelancer.com?
1. If you have money in your Freelancer account and you are not using your account, Freelancer.com will slowly and silently bleed the money from your account, currently 10 USD a month. The reasons listed on their website for this "maintenance tax" don't make much sense:
User Accounts that have not logged in for six months will incur a maintenance fee of up to $10.00 USD
per month until either the account is terminated or reactivated for storage, bandwidth, support and
management costs of providing hosting of the user's profile, portfolio storage, listing in directories,
provision of the HireMe service, file storage and message storage. These fees will be refunded upon
request by users on subsequent reactivation.
Let's look closely at some of these points:
a. storage; these days you can rent virtual machines for pennies; It's nothing special to get a fully fledged VM for as low as 2-3 USD a month. Such a machine includes TB of storage. Ex, Hetzner:https://www.hetzner.de/cloud?country=us
offers a VM for less than 3 USD with 20 TB of storage and ultra-fast NVME drives.
If you are looking for cheaper options, shared hosting will cost even less.
That being said, to charge 10 USD a month for storing a few MB of data (as most users have) is simply corporate GREED. If anything, Freelancer.com should be glad that people keep their profile there so that they can start offering services immediately if they want to.
b. bandwidth - the account is inactive, how much bandwidth can it use since nobody is checking the profile? Big companies rent or colocate physical servers or they own their own DCs. Bandwidth in these scenarios is not purchased per MB,TB or whatever but in terms of guaranteed bandwidth available.
I cannot image for a second that Freelancer.com is actually paying their bandwidth per MB, so that they would be concerned about bandwidth used by profiles that don't make money as of right now.
c. support and management costs of providing hosting of the user's profile, portfolio storage
What support? What management? Are these people serious?
You can read for yourself the rest of the claims as they fall in the same category as the ones above.
2. If you move from Free account to a paid plan then it will be quite a challenge to get back to the Free plan. If you don't pay attention to the plans, Freelancer.com will bleed 1 EUR a month or more from your bank account.
How does this scheme work? You check the plans carefully, you are now on FREE. You upgrade. In due time, you decide that you can go back to the FREE plan. The page with the plans is just as you remember it. You don't check the details again, after all, you remember that the FREE plan is the one on the left (the first plan with the least amount of options). You click on it, you are downgraded- confirmation is shown and you think you are done. 30 days later, Freelancer.com charges you 1 EUR. You wonder why! Check the plans again, the FREE plan is GONE. It's not possible to downgrage to FREE again because FREE doesn't exists in the list of offers any longer!
At this point, you Google for a solution and you find out that in order to actually get back to the FREE plan you must go to a hidden page, where you must click on Cancel Subscription. When you Cancel the subscription, you are being downgraded to the FREE plan.
Clearly, this is a deceptive tactic: most people would not even notice that a small amount is taken from their accounts. After all, when looking for something suspicious, you will probably ignore 1-2 USD charges as is very hard to remember where/when you have all your coffees :)
This is exactly the kind of behavior that Freelancer.com capitalizes on. You will not pay attention and on a big scale, they will make a lot of money. If there are millions of users that in time have downgraded their accounts to "FREE", then there will be millions of dollars worth of revenues taken silently from their user-base.
3. When a job is Canceled due to poor freelancer performance for example, the money will not come to your method of payment as you would expect. The money will go to your Freelancer.com account and you need to follow extra procedures to get your money back.
This practice is in line with the other dubious practices. If you will not invest more time to get the money into your account then you will most probably loose them in one way or another.
4. Freelancer's TOS has many dubious claims. I will emphasize just one
"Inactive Account" means a User Account that has not been logged into for a 6 month period,
or other period determined by us from time to time.
In other words, an "inactive account" can be any account that Freelancer.com decide it to be. You can be inactive if you haven't logged on the site in the past 24h. The TOS leaves this possibility open because the definition of "inactive" is very loosely defined. That means that Freelancer.com can always take money from your account based on "inactivity".
1. Freelancers on Freelancer.com don't read the job descriptions. They only look at the the budget boundaries. For any project you put there you will get a ton of offers in the first few minutes. Clearly, all those people have no time to look at requirements carefully.
This behavior of freelancers is modeled by another bad business practice, namely the offers are public. It makes no sense as a freelancer to carefully craft a response to the job poster, as any other fellow freelancer would be able to copy the most useful parts.
Again, Freelancer.com greed hits hard both the freelancer community and the companies that use the service. The offers are public by default, because freelancer.com wants to charge more money for private offers.
That summarizes Freelancer.com's services. But why is Upwork better? Upwork is much better because:
1. They have no dubious business practices (ex: when you cancel a project, you get the money into your bank account, not into your Upwork account)
2. Freelancers tend to read the job description much more often than the freelancers from Freelancer.com and the offers made by said freelancers are better suited for the project. Because the bids are private, the freelancers spend more time on creating them.