You have a homepage mockup to send back to a client by end of day. Do you spin up a Markup.io project, invite the client, walk them through how to leave comments, and manage the versions inside it? Or do you capture the screen in a browser tab, talk through your notes, and paste a link into the email thread you are already in?
Both tools exist for a reason. Markup.io is built around the agency review cycle: a project, a client, multiple rounds, comments threaded against versions. Cobalt Capture is built around one job: send feedback someone can act on, right now, without setting anything up. Picking between them is mostly about how much structure the work actually needs.
What Markup.io is genuinely good at
Markup.io treats a website or PDF as a living artifact your client returns to. You add a URL or upload a file, invite reviewers, and comments live against that artifact over time. When you push a new version, prior comments are still there to reference. For an agency running four-week design sprints with two or three formal review rounds, that continuity matters. The client logs in, sees the project, sees what was addressed, and sees what is still open.
If the same client reviews ten deliverables a year and you want a tidy record of every round on every page, a project-based tool earns its keep. The overhead of inviting people and setting up the project is amortized across months of work.
What a quick review link is good at
A quick review link inverts the model. There is no project. There is no invite. You open a tab, click Capture screen, share the window the browser asks about, and the current frame becomes an item you can comment on by typing or dictating. Add a few more captures, drop numbered pins on the spots that matter, and publish. You get a public URL at /r/<slug>, plus a PDF and a Word doc if the receiver prefers those. The whole flow takes a few minutes, and the person on the other end clicks the link and reads. No login on either side.
This is the case the Markup.io alternative for one-off reviews is built for. You are not managing a relationship inside the tool. You are sending one piece of feedback and getting back to your day. If your work fits that shape more often than it fits the project shape, the lighter tool wins on time per review.
The dimensions that actually decide it
| Dimension | Markup.io | Cobalt Capture |
|---|---|---|
| Setup before first comment | Create project, invite reviewers | Open tab, capture, type or dictate |
| Account required | Yes, for owner and usually reviewers | None required to publish or read |
| Install or extension | No install; extension available | No install, no extension |
| Versioning across rounds | First-class | Not a feature; each review stands alone |
| Comment threads over time | Yes, with resolve states | Per-item comments with resolve, per review |
| Output formats | In-app project view | Public link, PDF, Word, markdown |
| Price | Paid plans | Free |
The honest read: if your work is a long-running client relationship with formal rounds, Markup.io's structure is the point. If your work is mostly one-shot reviews scattered across the day, that same structure is friction.
Who each option actually suits
Markup.io fits agencies and in-house teams who want one place where a client logs in to see everything they have ever reviewed. It fits work that is genuinely versioned: a homepage that ships v1, v2, v3, with feedback carried forward. It fits clients who will tolerate, or even prefer, a login and a portal.
Cobalt Capture fits the rest. Freelancers reviewing a developer's staging build. PMs sending notes on a competitor's pricing page. QA leads filing one-off bugs against a release candidate. Marketers reviewing a vendor's landing page draft. People who need to send structured client feedback on something small without onboarding the client into a tool first. People doing staging site review where the next step is an email to the developer, not a portal visit. People running a quick design review pass on a Figma export.
There is also a developer angle worth naming. The markdown export at /r/<slug>/markdown is plain text a coding agent can read directly, which matters if you hand work to Claude Code or a similar agent after the review. Markup.io's value is the human-facing project; Cobalt Capture's output also covers the machine-facing case when you need it. That is a tie-breaker, not the main argument.
The mixed model most teams actually use
You do not have to pick one tool for everything. A reasonable split: keep your big retainer clients in Markup.io because the round-over-round history is worth the setup, and use a no-extension capture flow for everything else. The one-off review of a competitor site, the quick note to a developer about a broken form, the screenshot you need to send a vendor: none of those need a project.
If you want to try the lighter side of that split, start a review with no signup and see how long it takes to get a shareable link in front of the person who has to fix the thing. If it takes longer than writing the email, the tool is wrong for the job.