ProZ.com, Inc. Reviews 

They only seem to be interested in one thing - to get your membership fee. Since I do not pay others for my own hopes I never paid. Otherwise it is just another bidding site. I only went there because someone wanted my ProZ profile and I made it but since then I never heard from that someone again. Better keep that money for yourself.
And, yes, anyone can claim to be a translator there. Serious agencies give you a test. You may find out that your fields of expertise do not match their requirements (there is no such thing as a universal translator) and usually it is not so easy to start with an agency even if you pass the test but at least you can expect some result. And it does not cost anything, maybe except the price of printing out a paper contract and sending it to the agency. But not a membership fee for being on their list.

I found that a lot of scammers contacted me from ProZ and I got more trouble from them than help. Another thing I found to be a turn off is that when other members found I was talking a certain language, they contacted me, making nice with me over the phone, finding out how much I charge, what are my clients, only to find out that they were doing that to find out what kind of competition I am for "them". When I would contact them to ask advice, or to just say hi, they ghosted me.
Overall, ProZ lured me in(joining a facebook group required a ProZ membership), but once I was in, I didn't gain anything out of it, except I paid them money, or except "a taking" on their part happened. There was no community- but just folks trying to find out about you, what you do so they can discredit you on some level.

I disagree with the negative comments posted here: I've now been working as a freelance translator for 8 years, and that would never have happened without ProZ.
ProZ offers a great meeting space for freelancers and outsourcers/translation agencies. But that's what ProZ is: a meeting platform. Translation jobs are not magically going to land in your inbox simply because you registered on the platform. As a freelancer, you need to put the work in: build a solid profile, with translation samples to showcase your skills, do a few pro bono jobs and then request feedback to have something to show to potential paying clients, customise your application for each job to show you are the right translator for this specific project, instead of sending the same template to every outsourcer, etc.... And yes, paying members get a lot more benefits and work opportunities, but ProZ is not a charity, they need income to provide their platform to you! So if you are not ready to do all this, then your paying membership will be a waste of money, but if you are, the return on investment is well worth it.
And of course, ProZ can't guarantee that the outsourcer will pay you on time, or that the translator you hire is qualified or reliable, but they have feedback systems in place for both, and they flag up outsourcers that have been consistenly reported for non-payment, so I really think they're doing what is reasonnably possible here.
My one strong criticism would be the way translators are ranked in search results: the rankings are mainly based on the level of participation to their terminology Q&A page for translators (called KudoZ), which is not fair, or representative of the translator's skills/experience.
But, if you're a real, talented translator (not someone who think they can translate because they are vaguely bilingual), and if you have a bit of common sense and business sense, ProZ is a great place to start.

Terrible support
It's an OK site for being contacted by agencies once you've been a member for a few years, but they go out of their way to support dishonest agencies and not their paying customers.

I have now been reached 3 different times by 3 different people/3 different emails all with the same pretense of wanting to hire me for an English to Spanish translation, always using the same document and with the same scheme. The first time I had my doubts but followed through with the back and forth communication until I received a check from them, delivered by UPS. They attempted to pay me over $4K “in advance”, I called the bank the check came from and they confirmed the account had been closed and the check was fraudulent.

Anna Verbuk has been translating from English to Russian in support of MAPS: the Marine Arctic Peace Sanctuary being established as quickly as possible. Her work has been exemplary, and we are grateful to have found her!

Unethical service!
As a translation agency we have been targeted by a group of translator who used Google to translate a large assignment for us. We ended up paying a large sum (over 400.000 USD) in damages to the client and did not pay for the translation these people made.
They used Proz to taget us. We provided proof to Proz in form of documentation from our lawyer and Proz still keeps the negative remarks about us on the site.
We consider Proz to be a place were you find amateur translators, the real ones you find among those listed but the different organisation that organises translator like ATA etc. The management of Proz lacks every form for decency, are unethical and this is clearly why Proz is going down the drain.

Proz.com is a leading Company that offers translations!..Actually, it's a great platform for finding translation jobs in all language pairs, frequently updated. Thus outsourcers get in touch with employers, who ask in advance for certain qualifications from translators, thus whole procedure is not done in blind, say so!
Translators create their profile, with their strong language pairs, and their resule can be updated any time!
Proz has a well structured site, although very big it's easy to explore, all parts, due to its good structure and organization! Proz also offers translation possibility itself online, such as ask and answer Kudoz questions, which has mainly to do with rare words and phrases in all language pairs, all fields, thus translator can share his/her work in a cooperative way and tests his/her own abilities at the same time! Proz also offers other possibilities for translators, such as create invoice for clients online after having finished a job, and on the other side, outsourcers can post translation tasks waiting for replies!-There are other possibilities also, such as sale/purchas of CAT Tools, translation of Glossary, and Glossary creation, for professional translators.
All this and more, makes Proz a first class online platform and Leading Provider! Highly recommended; with Proz an experienced translator, but also a beginner can be sure, they'll never stay without work!!

I have built my career from this platform. Nothing in this platform is bad. Yes, they are developing day by day, but you see, to maintain a good market, sometimes you need to be not easy to access in all the fields. I am totally satisfied with proz.com and wish their success.

I created a free profile in Sept 2017 but have never signed up to be a member because I wanted to see what value they might bring. Since then I have been using the site for occasional live requests for help and a lot of work queries.

Observations:

(1) Other translators have been helpful although not all gave reliable advice

(2) The Kudoz points-based system is odious and counter-productive as it introduces an unnecessary and unpleasant undertone of rivalry between translators

(3) Those who do offer to help others - as I did on several occasions - find themselves under sudden verbal assault from an 'editor-at-large', whose identity and credentials are hidden. I did complain and ask ProZ support but the site-owners told me that this information was top-secret. Not surprising given the way this individual prowls around the site peremptorily and rudely 'correcting' any contributions he/she regards as not up to the mark.

Most off-putting and needless to say I know longer feel inclined to contribute if all I get is an abusive troll tracking my every step.

(4) The there are the agencies. As others have also remarked, a large number of these are fraudsters. So much for vetting and quality control.

(5) Translation support - I can see why in the past, over 10 years ago, say, this was a great idea, but today, with the development of AI and really superb online dictionaries and corpora such as the OED, I am finding all my requirements are now increasingly amply met without the need to refer to ProZ.

So, all-in-all, ProZ seems to be crumbling away. I don't think it's a good investment anymore, and would recommend migrating to LinkedIn. Much more professional and it has Microsoft behind it.

A company that lost its touch. Lots of registered users (agencies and translators) but less and less activity. Also, at least 50% of the thousands of agencies are outright scammers or companies in serious financial trouble.
The companies that still have a good reputation mostly do not use Proz for their 'first choice translators' selection but instead only go to Proz if they are desperate, so only for 2nd or 3rd choice. Those companies now have their own databases and portals for translators. So, if one is lucky from the on Proz listed translation jobs one will get the left over 'one time' job crumbs and usually urgent ones only. One will rarely get the opportunity to become a 'first choice translator' regardless of great online reputation, experience and qualifications.
Pity, but the whole 'directory-idea' like this is going the way of the dodo because the directories offer little useful functionality for translators and instead mainly cater to agencies, not understanding that without translators there are no agencies going to the site. Translators ought to be the first priority. Not worth the money anymore.

Excellent site, the right place for professional translators. I have been part of the community for some time and I find it really helpful.

Very poor customer service team, slow turnaround times, and generally unprofessional.

I was not surprised to see so many other users reporting similar issues - unfortunately, it seems that bad management and unskilled staff are the root of these problems and they are therefore unlikely to go away anytime soon.

Most dishonest site out there. If there would be a prison for internet wrongdoing, these guys would be in there forever.

I've created a new profile yesterday or the day before and they deleted my account for no reason, no warning, no notification but somehow they still kept my email in their data base to send me marketing email. I thought that this is a professional platform but I guess I was wrong. Very unprofessional.

Now I wonder how trustworthy is the info on their platform.

Useless website, very difficult to navigate through and of the many emails I sent out offering work, not one reply. They all can not be busy!

Terrible and fraud website without customer service and mobile version. 99% jobs are fake and with a 12 hour access restriction. They ask 1$ to even bid for a job. Just a fraud website.

I have been a member of Proz.com since 2010 and recently upgraded my membership and I am very disappointed on how long it takes to get a response even with having sent support documents, evidence all the e-mail correspondence between the agency and myself and given no feedback as to how I can activate a negative entry on this agency in order to be paid and to alert other paying member translators.

The site says translators can post BlueBoard entries on translation agencies profiles to let other tranlators know of their experience with such agencies. But that's not true. Proz.com blocks negatives entries, especially feedback reporting non-payment. I have been scammed by a translation agency and Proz.com doesn't allow me to report it

Scammers
They pretend to have professional translators listed on their site but the fact is that anybody can list and pretend to be a professional translator. There are NO checks at all of the people listed!
We ordered a translation, payed a large sum of money up front and got crap back!