Cold Email Benchmark

What is the average cold email open rate?

The median open rate across all countries is 26% (37,000 campaigns, agencies excluded). France (38%) and Germany (36%) lead; the US sits at 23% overall, or 26% once very high-volume senders are taken out of the US cohort.

Agencies excluded. "US (no large-scale)" removes very high-volume senders from the US cohort.

What is the best cold email subject line length?

Short subject lines open better, but the effect is smaller than the advice you usually hear. In the US, subjects of 10–19 characters get a 30% median open rate against 23% in the 60–69 character bin (~400 US companies). Outside the US the curve is the same shape but flatter and higher — 34% down to 28%. Replies point the same way: subjects of 20–29 characters have the best reply rate in both populations.

Bin 10 = 10-19 characters, 20 = 20-29, and so on. Email number 1 only (no follow-ups), mailboxes with at least 500 emails sent, one vote per company per bin. Row n = unique companies in the bin.

Bin 10 = 10-19 characters, 20 = 20-29, and so on. Same filters as the US chart. Row n = unique companies in the bin.

How many words should a cold email subject line have?

Fewer words open better. Worldwide, 2-word subjects get a 32% median open rate and 11-word subjects 24% (9,000 campaigns). The 1-word bin looks best of all at 39%, but it rests on 56 companies — do not over-read it. Reply rates peak a little later, at 3–4 words (1.20–1.29%).

Row n = unique companies in the bin. The 1-word bin has a very small sample (56 companies) and should not be over-read.

Row n = unique companies in the bin. The tail bins (9-11 words) rest on 32-42 companies each.

Row n = unique companies in the bin. The 1-word bin has a small sample (40 companies).

Which email provider gets the best cold email results?

Across the six providers with at least 100 mailboxes in the sample, median open rates run 22–38% and median reply rates 0.52–1.33% (4,713 mailboxes / 1,738 companies across all providers). G Suite leads on opens (38%) and CUSTOM domain mailboxes reply best (1.33%); SendGrid trails on both counts (22% open, 0.52% reply). Leave SendGrid aside and the five mailbox providers sit in a tight band: 31–38% open, 1.01–1.33% reply.

Providers with fewer than 100 mailboxes in the sample are left out of this table — their medians rest on too few mailboxes to compare. The population above covers every provider in the data; the grand total across all of them is 34% open and 1.16% reply. Global figures, agencies excluded.

What is the best day to send cold emails?

The day of the week barely moves opens: Monday to Friday all sit at a 32% median open rate, and the weekend only drops to 29–30%. Replies are where the difference shows up — weekend replies run about 38% lower than weekday replies, even though the weekend carries roughly a fifth of the weekday sending volume. The quieter inbox does not pay for the worse odds.

Open rates are identical across workdays and only 6-9% lower on the weekend, but reply rates drop by about 38%. Only a quarter to a third of companies send on the weekend.

How many follow-ups should a cold email sequence have?

Every follow-up is less effective than the one before it: email 1 gets a 1.0% median reply rate, email 4 about half of that (0.5%), and emails 5–6 roughly 30% of email 1's reply rate — 1,020 companies (campaigns with 4-6 emails). One follow-up is still clearly worth sending — in 2-email campaigns the follow-up replies at 1.4% against 1.2% for the first email (1,272 companies).

Mailboxes that sent at least 100 emails, campaigns with 4, 5 or 6 emails in the sequence. Email 4 is only half as effective as email 1; emails 5 and 6 about 30% as effective. Campaigns with 7+ follow-ups were excluded as a low-quality cohort.

Do smaller cold email campaigns get more replies?

Yes, and the curve is steady all the way down. Independent companies get a 2.7% median reply rate on campaigns of 0–50 prospects and 1.2% at 1,001–5,000 — a bit over double (2,623 companies / 19,870 campaigns). Agencies run the same curve from 3.0% down to 1.1%. Both cohorts land near 0.5% once a campaign passes 10,000 prospects.

Median reply rate by campaign size — independent companies (2,623 companies / 19,870 campaigns). Non-agency companies. Campaigns started and completed within the 90-day window. Cohort total: 1.9% median reply rate.

Median reply rate by campaign size — agencies (799 companies / 3,126 campaigns). Campaigns started and completed within the 90-day window. Cohort total: 1.9% median reply rate.

How does bounce rate affect cold email results?

List hygiene shows up in replies. Campaigns kept under a 2% bounce rate get a 1.6% median reply rate — about 60% more replies than the 0.9–1.0% reply rate of campaigns bouncing over 20% (56,614 campaigns / 7,000 companies). Two thirds of all campaigns already land in the cleanest bin, so a high bounce rate puts you in a small and badly performing minority.

Grand total: 33% open, 1.5% reply. A campaign under 2% bounce rate has about a 60% higher reply rate than campaigns bouncing over 20%. 65% of all campaigns land in the 0-2% bin.

How many cold emails should you send per day?

Volume per mailbox is the steepest curve in this whole data set. Mailboxes that average 1–20 emails a day have a 2.0% median reply rate — four times the 0.5% reply rate of mailboxes sending 101–200 a day — and a 41% median open rate against 23% (7,676 mailboxes that sent at least 500 emails in the last 90 days). These medians are per mailbox, not per company.

Grand total: 27% open, 0.9% reply. Mailboxes sending 1-20 emails a day get 4x the reply rate of mailboxes sending 101-200. The 2000+ bin rests on only 6 mailboxes.

How much does cold email cost compared to other channels?

Outbound email has the lowest cost floor of any channel in this comparison: $1.66–$28.3 per acquisition, against $41–$163 for LinkedIn ads and $160–$324 for events and trade shows. At an average deal size of $2,000, an average campaign returns $6 for every $1 spent, and a top-5% campaign $119.

The return figures assume an average deal size of $2,000. The three scenarios are real Woodpecker campaigns — an average one, a good one and one in the top 5% by cost per lead — not medians across the platform; the positive reply rate was only recorded for the better two. The outbound email range in the channel table is the same $1.66–$28.3 cost-per-lead range; the other channels are published industry ranges, not Woodpecker data. The chart compares the low end of each range — the table carries both ends.

Methodology

• All numbers are medians from campaigns sent through Woodpecker in the last 90 days of 2025.
• Agencies excluded unless stated otherwise.
• Medians per fixed company (firmid) unless stated otherwise.
• Headline reply median uses the bounce-table grand total (largest campaign population).
• Open rates are affected by tracking limitations (e.g. Apple Mail Privacy Protection).
• Segments with very small samples are excluded from comparisons or marked accordingly.
• Cost-per-acquisition figures for channels other than outbound email are published industry ranges, not Woodpecker data.