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Annotation that learns, with review built in

Every model needs an editor.

Get your data annotated by a model that gets better every month. It labels what it's sure of in about 100 ms, and your team checks the rest in a review screen that comes with every workspace. Each correction trains the model on your own data, so next month fewer items need a person.

Start free See how it works

2,000 free credits a month. Reviews by your own team cost nothing. Crowd review is on a waitlist.

val_7Q2M4K task doc-tagging · mode auto · your team
Field
Your model said
Margin
communication_type
News Article‸Press Release
‸ your team
machine 0.41
company
Halvard Air
stet ✓
machine 0.98
crisis_mention
false
stet ✓
machine 0.97
executives
Mara Lindqvist, Owen Achebe
stet ✓
machine 0.93
product_launch
false
stet ✓
machine 0.96
Corrected · 1 of 5 fields 41 min · webhook 200
01 / Ladder

Cheapest reviewer first. A person only when it's unsure.

Each item starts on the lowest rung that is calibrated for your task. It climbs one rung whenever confidence falls under your threshold.

RungWho answersTimeBest for
Fast A small model trained on your task's golden set. It runs on our machines, so your data stays with us. ~30 ms High volume, once you have a golden set
Decision model Answers typed questions with calibrated confidence. No training needed. ~100 ms Day one, before a golden set exists
Frontier model For ambiguous items. Its answers also draft training labels for the rungs below. seconds Edge cases and long documents
People Your own team, in the review screen built into the console. Later also the annotators.org crowd, with several people per item when it matters: join the waitlist. minutes to hours Whatever the machines doubt
Worked example · a 100,000-document tagging stream, 8% escalated
Sent to annotators.ai
100,000 Approved by the machine
92,000 Checked by your team
8,000

Every correction comes back to you by webhook and becomes a golden-set candidate.

02 / Review

A review screen comes with every workspace.

Your team checks what the machine doubted, in the same console as your annotations. Reviews by your own people are free: no labeling tool to buy, no export, and nothing leaves your workspace.

Review · doc-tagging3 waiting · 1 done
Halvard Air names Mara Lindqvist chief executive

FOR IMMEDIATE RELEASE

Stockholm, 21 October 2026. Halvard Air today announced that Mara Lindqvist will become chief executive on 1 January, succeeding Owen Achebe…

communication_type machine doubted
1Press Release
2News Articlemodel
company
1Halvard Airmodel
1–9 chooseA keep all↵ submitS skip

See what the machine doubted

Each item shows the model's answer and marks the fields it wasn't sure of. Keep what's right, fix what isn't.

Corrections train your model

Every fix becomes a golden-set candidate. Approve it, and the task's model learns from your own data.

Bring help when you need it

Invite contractors or a BPO by email. They review your private items in the annotator app.

Crowd review Waitlist

The annotators.org network takes what your team doesn't get to: like Mechanical Turk, with a published pay floor and scores reviewers can see. Join the waitlist.

03 / Integrate

One call, after the one you already make. Or instead of it.

No new labeling tool, no model switch, no data migration. Send output from any model to have it checked, or leave it out and we label the item.

from annotators import Annotators

client = Annotators()                      # reads ANNOTATORS_API_KEY
tags = my_model.tag(doc)                   # the call you already make

client.annotate(
    "doc-tagging",
    input={"title": doc.title, "content": doc.text},
    output=tags.fields,                    1
    source={"model": "my-model", "confidence": tags.p},
    mode="auto",                           2
    callback_url=WEBHOOK_URL,              3
)

# later, at your webhook
{
  "type": "annotation.completed",
  "data": {
    "id": "val_7Q2M4K",
    "verdict": "corrected",
    "corrected_output": {"communication_type": "Press Release"},
    "agreement": 1.0,
    "resolved_by": "human"
  }
}
1Whatever your model returned. Any model, any provider. Leave it out and we label the item from your examples.
2auto: the machine checks first. Your reviewers see only the items it doubts, with those fields marked.
3Verdicts arrive by signed webhook, with retries. Or wait for one with hold=True.

Also as an MCP tool, request_human_review, so agents can ask for a check on their own work.

Get an API key · API reference

04 / Modes

From machine only to people on every item.

auto

The default. The machine checks every field; people review only what it doubts, and they see which fields those were.

Most items never reach a person.

machine

Machine only. Items it's sure of come back approved or labeled; the rest come back marked low_confidence, and you decide what to escalate. Nothing reaches a person.

For bulk labeling, or pipelines with their own fallback. Cheapest, and nothing waits on people.

human

Every item goes to people, with as many reviewers per item as you ask for. Disagreements add a reviewer, up to five.

For high-stakes output and building a first golden set.

sample

A fixed share of a stream, 5% by default, goes to people and the rest passes through. You get a running accuracy number for any model, including yours.

Audit mode for production models.

Every call is an audit or a gate. By default your result has already shipped and a correction arrives later. Set hold and your call waits for the verdict; held items are reviewed first.

ai_assistanceLet reviewers use AI and pay less, or require human judgment only.
redundancyOne reviewer or five. Majority verdicts with agreement scores.
accept_thresholdHow sure the machine must be before it approves on its own.
05 / Workforce

You decide who sees your data.

Today your own team reviews, in the console or the annotator app. Crowd review from the annotators.org network is on a waitlist, and sensitive work never goes to it.

WorkforceWho reviewsData exposure
privateYour team in the console, plus staff, contractors or BPO you invite by email. Free.Never leaves your team
open WaitlistQualified annotators.org membersNon-sensitive data only
vetted WaitlistMembers with a strong check record and a domain test: finance, legal, multilingualUnder our NDA
dedicated LaterNamed vetted annotators assigned only to youUnder your NDA
06 / Golden set

Annotations that get better every month.

Approved corrections become the examples the machine labels from. Its answers get more accurate, fewer items reach people, and cost per item falls.

1

Your team corrects an item

A reviewer fixes what the model got wrong, right in the console.

2

It becomes a candidate

Unanimous corrections queue up as golden-set candidates.

3

You approve it

Approved items become check items for reviewers and training data for your task.

4 → 1

The machine learns from it

Its next annotations are more accurate, so more resolve without people.

07 / Surveys Crowd panels: waitlist

Need opinions, not labels?

Send a message, headline, ad or document and get responses from real people: sentiment scores, choices and verbatims, with speeders and AI answers filtered out. Run it next to your synthetic audience and see how close it really is.

Survey your own team today. Panels from the annotators.org crowd open with crowd review: join the waitlist.

Sentiment50 responsesShare
Very positive
14%
Positive
38%
Neutral
26%
Negative
16%
Very negative
6%
3 speeders excluded · AI assistance off
Crowd review · Waitlist

Need more hands?

Everything else is open now: start free, send work by API, and review it with your own team. The annotators.org crowd, for the items your team doesn't get to, opens in batches. Join the waitlist and we'll let you know.

Coming from Mechanical Turk, Ground Truth or A2I? Export your results before 30 Oct and tell us what you run. We'll help you move it.

Only your email is required.

For teams shipping model output

Check every output.

Audit a sample of a production model, or gate what ships. Corrections come back by webhook.

Start free
For people who want paid work

Earn as an annotator.

A published pay floor, paid from the first item, and a score you can always see.

Join the annotators.org waitlist