Machine Learning · head to head
Comet ML vs Rev
Comet ML
Machine Learning
Platform for tracking, comparing, and optimizing ML experiments
- From
- Free
- Free plan
- Yes
Rev
AI
Human and AI transcription, captions and subtitles priced per minute
- From
- Free
- Free plan
- Yes
The short version
- Each has a real cost: Comet ML the free cloud tier caps data at 25,000 spans a month with 60 day retention; Rev human transcription at 1.99 US dollars a minute means roughly 120 dollars an hour of audio, so a long-form interview series costs more in transcription than most teams assume before they run the arithmetic.
- They diverge on capability: Comet ML covers Experiment tracking, Rev covers Human transcription.
- Prices and features above were last checked on 31 August 2026.
Where they differ
Only the attributes on which Comet ML and Rev actually diverge.
Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).
What each one covers
Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.
Only in Comet ML
- Experiment tracking
- Code versioning
- Model registry
- Hyperparameter optimization
- Production monitoring
- PyTorch
- TensorFlow
- Keras
Only in Rev
- Human transcription
- AI transcription
- Captions and subtitles
- Legal transcripts
- File analysis
- Clio integration
- Rev API
- Speaker identification
What people use each for
The jobs each tool is most often brought in to do.
Comet ML
- LLM observability and monitoringnot Rev
- AI agent testing and debuggingnot Rev
- Experiment tracking for machine learningnot Rev
- Model registry and version managementnot Rev
- ML model training monitoringnot Rev
Rev
- A law firm that needs a deposition transcript in a court-acceptable page format with a fixed turnaround and a published per-page price it can bill to a matter.not Comet ML
- A documentary or podcast producer costing a project in advance, because human transcription at a published per-minute rate makes the transcription line item a known number.not Comet ML
- A broadcaster needing compliant human captions rather than machine captions, where accuracy is a regulatory requirement and not a convenience.not Comet ML
- A team with high AI volume and occasional high-stakes files, using the subscription for the bulk and paying the discounted human rate only where accuracy matters.not Comet ML
Where each one falls short
Documented limitations, not opinions. Every one is a constraint you would hit in normal use.
Comet ML
- The free cloud tier caps data at 25,000 spans a month with 60 day retention
- Retention stays at 60 days even on the paid Pro plan, and extending it is a $29 per 100k spans add on
- Overage on Pro is $5 per additional 100,000 spans
- The free MLOps tier is a single user with 100 GB of storage and training hours governed by a fair usage policy
- Pro MLOps is $19 per user per month and caps the team at 10 users
Rev
- Human transcription at 1.99 US dollars a minute means roughly 120 dollars an hour of audio, so a long-form interview series costs more in transcription than most teams assume before they run the arithmetic.
- AI minutes are allocated per seat per month and do not roll over, so bursty workloads, which is how most media production actually behaves, waste allowance in quiet months and run out in busy ones.
- The product direction has moved towards legal and investigative use, so a newsroom or media buyer is choosing a tool whose roadmap priority sits elsewhere.
- Foreign-language subtitles are priced from 6.49 to 15.99 US dollars per minute, an order of magnitude above transcription, which makes multi-language localisation of any volume of video expensive enough to change the plan.
- Human turnaround is stated in hours rather than guaranteed contractually on the published plans, so a hard broadcast or filing deadline needs an agreement beyond the standard terms.
Pricing, plan by plan
Comet ML
Free- Free CloudFree
- Up to 10 team members
- 25,000 spans per month
- 60-day data retention
- Pro Cloud$19/month
- Up to 50 team members
- 100,000 spans per month
- 60-day data retention
- MLOps FreeFree
- 1 user with fair usage policy
- Experiment tracking
- Dataset management
- MLOps Pro$19/user/month
- Up to 10 users
- 1,500 training hours included
- 500GB storage included
Rev
Free- FreeFree
- 45 AI transcription and caption minutes per month
- Up to 5 files analysed
- No human transcription included
- Essentials$25.49/month
- 5,000 AI minutes per seat per month
- Up to 3 seats
- 10 per cent discount on human transcription, captions and subtitles
- Pro$47.99/month
- 10,000 AI minutes per seat per month
- Up to 5 seats
- 15 per cent discount on human work
- Unlimited$undefined/month
- Unlimited AI minutes
- Up to 500 files analysed at once
- Dedicated account specialist
Which should you pick?
Choose Comet ML if
- You need experiment tracking.
- You want to start without paying.
- You work on Web, Linux, Mac, Windows.
- You also want code versioning.
Choose Rev if
- You need human transcription.
- You want to start without paying.
- You work on Web, iOS, Android, API.
- You also want ai transcription.
Questions people ask
- Is Comet ML or Rev better?
- Neither clearly leads. Comet ML starts at Free and Rev at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
- Which is cheaper, Comet ML or Rev?
- Comet ML starts at Free and Rev at Free.
- Does Comet ML or Rev run on more platforms?
- Comet ML runs on Web, Linux, Mac, Windows. Rev runs on Web, iOS, Android, API.
- Can I use Comet ML for free?
- Both have a free tier, so you can try either at no cost before committing.
- What is Comet ML best used for?
- Comet ML is most often used for llm observability and monitoring, ai agent testing and debugging, experiment tracking for machine learning, model registry and version management. Of those, llm observability and monitoring and ai agent testing and debugging are not what Rev is typically brought in for.
- What can Comet ML do that Rev cannot?
- Comet ML covers Experiment tracking, Code versioning, Model registry, Hyperparameter optimization. Rev covers Human transcription, AI transcription, Captions and subtitles, Legal transcripts.
Answered from the vendors’ own pages
Comet ML: Does Comet.ml offer a free plan?
Yes, Comet.ml offers free tiers for both Opik (cloud observability) and MLOps platforms. Free Cloud Opik includes up to 10 team members and 25,000 spans/month. Free MLOps tier is limited to 1 user.
SourceRev: How much is human transcription?
1.99 US dollars per minute with a stated accuracy target above 99 per cent, typically returned within 12 hours. Subscribers get 10 to 15 per cent off.
Comet ML: How many team members can use the free Comet.ml tier?
Free Cloud supports up to 10 team members. The Pro Cloud plan supports up to 50 team members at $19/month.
SourceRev: Is there a free tier?
Yes, 45 AI minutes per month and up to 5 files analysed, with no human transcription included.
Comet ML: What is a span in Comet.ml pricing?
A span represents a single tracked operation such as model requests or function calls. Free Cloud tier includes 25,000 spans per month.
SourceRev: Do unused AI minutes roll over?
No. The allowance is per seat per month and resets, which penalises irregular workloads.
Comet ML: Does Comet.ml offer academic pricing?
Yes, a free Pro plan is available for academic users; verification is required via signup.
SourceRev: Can it do subtitles in other languages?
Yes, across seventeen languages, priced from 6.49 to 15.99 US dollars per minute, considerably more than transcription.
Rev: Is Rev still a good choice for newsrooms?
It works, but the subscription tiers are now positioned around legal and investigative workflows, so a newsroom should compare it against a tool built specifically for journalism.
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